POS would be very beneficial for whales, but not so much for regular users. People with one or two ETH will not receive much reward, so there will not be an avalanche of regular people buying ETH, but whales accumulating. Therefore, the answer to your question is no.
I don't think we should focus on the reward aspect of POS, instead we should focus on the technical aspect of this implementaton.It's true that most of stake rewards will go to whales and that's normal, however when it comes adoption I think that POS improves scalability drastically like fast transactions,lower fees etc... Therefore,IMOHO, yes here will more adoption.
Please do no sugarcoat it with thoe good conclusions.
Bartolo is right the whales will be the winner here.
Adoption? ETH have been so long in the crypto industry and trust have been planted to many users. I dont think just because there will be a staking that will happen it would grow that fast. NO! Investors are staying because they have faith with ETH and not because of mere staking.
Yes it will help but never a full blast.