Yeah, they are their main Pokemon, so they must recognize their trainers's feelings.
Do you think Ash and Misty need someone to help them confessing their feelings? If yes, who?
I think someone would need to convince them for confessing their feelings now. I'd say Brock. Sure, he isn't very successful in love, but both Ash and Misty feel comfortable around him, and he must recognize their feelings. I think Brock can help both Ash and Misty to fully accept and confess their feelings.
However, if they would confess at a somewhat older age, they somewhat matured and might be able to confess without anyone pushing them to confess.