Should we expect a relatively big pull back in the short term (30%+) with the top 50 alt-coins in the next two months?
You have already done good research on the market and what you are expecting is to happen. I can see it has already started and it will continue till the halving is completed. The demand is only for Bitcoin and not altcoins as you said only those who have their bags full or those who are accumulating are trading in altcoins. There is less demand for altcoins it will be over if the spot ETF of Ethereum gets approved. Most of us doubt that it will get approved the first time, it will take some time and then we will see a rally in altcoins with the expectation that other altcoin ETFs might come into existence. Currently, the market is going through a correction but I do not think it will go down as you are expecting.