I would go so far as to say that by RAW it isn't allowed.
Metamagical Experimentation doesn't remove the requirement of meeting the prerequisites of the metamagic feats that you gain. It adds additional restrictions that it a) be a Metamagic feat, and b) be no more than half your level.
At best this is ambiguous since it doesn't say one way or the other. At which point the Ambiguous Rules rule would apply. And I would rule that gaining a feat without meeting its prerequisites is too good to be true.
In any case, this particular feat is not going to be a problem in about a month and a half. Conceal Spell by itself in the Remaster will do the full job of stealth casting.
I'm not sure why this thread was revived after so long, but the fundamental logic was flawed. There's no reason that the thesis would bother to say that you need to meet prerequisites. That doesn't need to be restated. I can't see even calling this ambiguous.
I made sure to have Conceal Spell so that my Wizard (with Rogue Dedication Feats) could take Silent Spell on those days that I wanted to be sneaky. It's worked out quite well.
Conceal Spell looks to be one of the Feats that will operate quite differently in the Remaster, and Silent Spell is simply gone.