Most definitely. Thermopylae is one of the few reliable land routes throuh the mountains that cut off Boeotia, Attica, and the Peloponnese from the Eurasian mainland. It's military importance and history was no secret.

Our most thorough extant source on Thermopylae is Herodotus' account from the mid 5th century BC. His work was familiar to Romans, as we see Cicero derisively call him out:

In history the standard by which everything is judged is truth, while in poetry it is generally the pleasure one gives; however, in the works of Herodotus, the Father of History, …one finds innumerable fabulous tales

You can see a bit of sarcasm in calling up this title, which must have been familiar to his readers/listeners. The event itself is mentioned by several authors. In the Roman-Jewish historians Flavius Josephus' The Jewish War (~70 AD), one figure gives a speech warning the Judeans of the power of the Romans, who had conquered even the Greeks, of whom he provides a list of their great feats:

And yet you [...] in your circumstances will venture to oppose the entire empire of the Romans. While those Athenians, who, in order to preserve the liberty of Greece, did once set fire to their own city; who pursued Xerxes, that proud prince, when he sailed upon the land, and walked upon the sea, and could not be contained by the seas, but conducted such an army as was too broad for Europe; and made him run away like a fugitive in a single ship, and brake so great a part of Asia at the Lesser Salamis; are yet at this time servants to the Romans; and those injunctions which are sent from Italy become laws to the principal governing city of Greece. Those Lacedemonians also who got the great victories at Thermopylae, and Platea, and had Agesilaus [for their king], and searched every corner of Asia, are contented to admit the same lords.

The Sicilian Diodorus wrote his sizable Bilbiotheca Historica some time around 50-40 BC, and it too contains an account of the Greco-Persian wars, including Thermopylae. The story of the battle was maintained up to, and long after, the Roman's 191 defeat of the Greeks.

Almost certainly. I will speak of Roman knowledge as I am much less familiar with the Seleucids, however they were a hellenistic culture so it is very likely with them as well. The primary source for the Greco-Persian Battle of Thermopylae is Herodotus' Histories.

In Rome, Greek literature was incredibly influential around the time of the Roman Battle of Thermopylae. Studies in Greek language and culture were incredibly common as a key part of education. There is even an example of Cato the Elder (who actually took part in the 191bc Battle of Thermopylae) quoted by Aulus Gellius comparing the actions of a Roman tribune in a battle in Sicily against the Carthaginians to the Spartan Leonidas at Thermopylae (The Cambridge Companion to the Roman Historians p.95)

There was also an epitaph generally attributed to Simonides of Ceos that was inscribed on a stone atop the Spartan burial mound at Thermopylae that read, according to Herodotus and translated by FT lucas as

Tell them in Lacedaimon, passer-by / That here, obedient to their word, we lie

Furthermore in the account of Appian regarding the battle, he speaks of how Antiochus

sent Aetolian troops to occupy the summits of the mountains to prevent anybody from coming around secretly by way of the hill called Atropos, as Xerxes had come upon the Spartans under Leonidas, the mountain paths at that time being unguarded.

So I would be very surprised if the Romans were unaware of what the Spartans had done at the same spot, and we know for a fact that at least one of them knew.