Those are pretty wild predictions. The last rally for Ethereum was based on the final specs for launch of ETH 2.0. I think people rushed for the 32 ETH requirement and that created this current price floor. Apart from that, there wasn't anything fundamentally new about Ethereum.
So expecting almost a 5X solely because of launching PoS is too optimistic. PoS has a different set of issues and hasn't really been done on this scale except in a fully centralized manner (as in case of Binance Chain).
In crypto, it is possible.
People did not believe that Ethereum can get its 2018 all time high, they said the altcoin will never touch that expensive price again.
Then what happened? Ethereum broke the cap $1,400 and soared to more than $4,100. They had many reasons to disbelieve in Ethereum because they saw Changpeng Zao shilled Binance Smart Chain and they can use BNB and that chain with very cheap transaction fee.
Ethereum will be like Bitcoin, beat all fud and opponents to get its new all time high. BNB can get a price of ETH in 2018 soon but it will need a few years to rise to $4,000 like ETH months ago.