From a Catholic perspective, why does Wisdom merely "infer" the things to come?

The Greek text of Wis. 8:8 states,

εἰ δὲ καὶ πολυπειρίαν ποθεῖ τις,

οἶδεν τὰ ἀρχαῖα καὶ τὰ μέλλοντα εἰκάζει,

ἐπίσταται στροφὰς λόγων καὶ λύσεις αἰνιγμάτων,

σημεῖα καὶ τέρατα προγινώσκει καὶ ἐκβάσεις καιρῶν καὶ χρόνων.

which is translated into English as,

And if someone also desires great experience,

she knows the ancient things and [εἰκάζει] the future¹ things

She knows subtleties of speeches and solutions of riddles.

She foreknows signs, wonders, and ends of seasons and times.

As the original question pointed out, the word in question is εἰκάζει, a verb conjugated from the lemma εἰκάζω.

As the original question also noted, this verb basically has three meanings:

1. represent by an image or likeness, portray
2. liken, compare; describe by a comparison. Pass. to be like; resemble
3. infer from comparison, form a conjecture

Although the verb εἰκάζω and its conjugations do not occur in the Greek New Testament corpus, the related noun εἰκών and verb εἴκω do occur, the former meaning "image; figure; likeness," and the latter meaning "to be like" or resemble.

In Heb. 10:1, it is written,

For the law having a shadow (σκιὰν) of the good, future things — not the very image (εἰκόνα) of the things — can never year-by-year with the same sacrifices which they offer make those who approach perfect continuously. ^{(KJV, 1769)}

σκιὰν γὰρ ἔχων ὁ νόμος τῶν μελλόντων ἀγαθῶν οὐκ αὐτὴν τὴν εἰκόνα τῶν πραγμάτων κατ᾽ ἐνιαυτὸν ταῖς αὐταῖς θυσίαις ἃς προσφέρουσιν εἰς τὸ διηνεκὲς οὐδέποτε δύναται τοὺς προσερχομένους τελειῶσαι ^{(TR, 1550)}

A σκιά is a "shadow" which is cast by a real object or reality, an εἰκών. The author states that the Law had a shadow of the good, future things (τῶν μελλόντων ἀγαθῶν), but not the reality — the good, future things themselves.

As far as εἰκάζει is concerned in Wis. 8:8, I doubt it means "infers," as though Wisdom does not know for certain, as that would contradict just one chapter later wherein it states that Wisdom "knows and understands everything."² Rather, let's suppose that it means "represent by a...likeness," and according to that sense, it means that Wisdom represents the future things by shadows or likenesses of their realities, just as the Law had shadows or likenesses of the good, future things (the realities themselves).

Thus, the English translation would be:

And if someone also desires great experience,

she knows the ancient things and represents the future things by shadows.³

She knows subtleties of speeches and solutions of riddles.

She foreknows signs, wonders, and ends of seasons and times.

Footnotes

¹ or "coming"

² οἶδε γὰρ ἐκείνη πάντα καὶ συνίει

³ or "likenesses." In Xenophon's Economics, Ch. 10.1, we find the phrase εἰ Ζεῦξίς μοι καλὴν εἰκάσας γραφῇ γυναῖκα ἐπεδείκνυεν, which is translated as, "...if Zeuxis showed me a beautiful woman he portrayed (εἰκάσας) in a sketch (γραφῇ)." The γραφή is a drawing or sketch, thus making it synonymous with σκιά which can also be used in the sense of sketch or representation of a reality. For example, St. John Chrysostom on Heb. 10:1:

For as in painting (γραφῇ), so long as one [only] draws the outlines, it is a sort of "shadow" (σκιά) but when one has added the bright paints and laid in the colors, then it becomes "an image" (εἰκὼν). ^{(Trans. Schaff)}

ἕως μὲν γὰρ ἂν ὡς ἐν γραφῇ περιάγῃ τις τὰ χρώματα, σκιά τις ἐστίν· ὅταν δὲ τὸ ἄνθος ἐπαλείψῃ τις καὶ ἐπιχρίσῃ τὰ χρώματα, τότε εἰκὼν γίνεται.

Undoubtedly we can say that Jesus' divine nature is omniscient, but your confusion could result from identifying Wisdom too closely with Jesus. In Luke 11:31-35, Jesus speaks of John the Baptist, himself and then Wisdom, but only in the third person and such terms that it would be difficult for us to think of her as his divine nature:

Luke 11:31-35: "Then to what shall I compare the people of this generation? What are they like? They are like children who sit in the marketplace and call to one another, 'We played the flute for you, but you did not dance. We sang a dirge, but you did not weep.' For John the Baptist came neither eating food nor drinking wine, and you said, 'He is possessed by a demon.' The Son of Man came eating and drinking and you said, 'Look, he is a glutton and a drunkard, a friend of tax collectors and sinners.' But wisdom is vindicated by all her children."

Jesus again refers to Wisdom in Luke 11:49, and again as if she is a distinct entity:

Luke 11:49: Therefore, the wisdom of God said, 'I will send to them prophets and apostles; some of them they will kill and persecute'

We know that Jesus is equated with the Logos (Word) in John's Gospel. Burton L. Mack says in Who Wrote the New Testament, page 264, that according to Philo, a Jew of the Alexandrian diaspora, Logos was God's son, through whom the world was created as a rational and ordered universe. Philo taught that the Logos was born of mother Wisdom and, appearing in the world, was the agent through whom the great leaders of Israel learned what God expected of them.

Based on the evidence of Philo and Luke, among others, it is not inconceivable that Jesus is omniscient whereas Wisdom was not, and only judges or infers things to come (Wisdom 8:8).

A further discussion on Wisdom is also provided by the Catholic Encyclopedia, which says (among other things) of Wisdom:

In direct relation to God, Wisdom is personified, and her nature, attributes, and operation are no less than Divine. She is with God from eternity, the partner of His throne, and the sharer of His thoughts.