There is little difference in footballing terms, though.
You're making out as if he has to be mollycoddled at 21 for one reason or another. Ronaldo came to England at 18, spoke very little English, played for arguably the biggest club in country and his father passed away before he turned twenty but despite all of that, he managed to thrive.
I know very little about Pulisic's character aside from him being rather quiet, but at some point he'll need to look at himself and find a way to get ahead rather than being being disgruntled at lack of opportunities or what not. One thing that I'm certain is, he won't be frozen out under Lampard this season.
You're dead cert on this loan idea, which could be the end for him should your wildest dreams come to fruition. He will probably find himself further down the pecking order (low standard as is) with us being able to freely move come next summer.
Noise coming out that he was subbed early due to illness rather than "tactical reasons". Either way, I agree with your view about the manager.