All those forecasts are absolute bullsit. People are pointing on the correlation between BTC price changes and tax year, bangladesh interest rate changes, penguin season migration etc. But no one was bothered enough to prove that this correlation really exist. If Tom Lee says that this somehow influenced the BTC price then I expect him at least to make a survey among the US crypto holders asking them why they bought / sold their coins and when.
No, this logic supports the price rise and doesn't indicate a dump is coming at all. Crypto doesn't work like normal investments, you have to pay tax on every "taxable event," not only capital gains when you sell. A taxable event is every time you exchange one coin for another, so if you buy Bitcoin and convert to XRP, that's a taxable event. You're liable for the taxes immediately, not when you sell the XRP. When you convert XRP back to BTC, that's another taxable event, and then another when you sell BTC back to fiat. So if you were trading a bunch of alts, you owe taxes before you convert to fiat, which is why (the theory goes) people needed to cash out crypto holdings to have enough money available to pay their tax bills. I don't necessarily buy the thesis, but I can say that you look foolish for criticizing an idea you didn't even understand.
The correlation supports the claim, it is not the cause of it.