I doubt it or at least he didn't seem to care. All he was worried about was waking Sora so he could take down the nobodies.
The digital Diz within Sora that Riku meet in DDD seems to be aware of it though. It's this digital Diz that points out how Riku meet "three young people" (Ventus, Xion, & Roxas) referring to them as individuals rather than just dreams or illusions.
Do not forget though that the real Ansem the Wise (as DiZ) created this digital version and imbued it with all his research results and knowledge.
In the secret ending of BBS FM (the infamous BBS vol. 2 one), we see DiZ uploading data into Sora while he's still sleeping in that pod nearby.
The digital Ansem only knows what the "real" one uploaded into him, which happened before Sora awakened anyways because Ansem himself said so to Aqua in Blank Points.
The second notion, that he didn't care (or rather was in denial due to be still in "revenge"-mode), is much more likely.
Ansem the Wise said:
A heart is so much more than any system. I saw it when Roxas and Kairi crossed paths. I knew. But I was too stubborn to accept it.
Blinded by his desires for revenge as well as both Roxas and Naminé belonging to the "species" he detested, to DiZ "For ... that which must not, cannot be."
One has to take notice though that DiZ seemed to have no tolerance for any being that wasn't born the "normal" natural way, as he called Xion a "blasted puppet" as well.
Yea, that's because they were at the core of Sora's heart there, and with Roxas, Ven and Xion as well as the digital Ansem all there it proves they're really all inside Sora's heart.
