I believe that as long as Bitcoin will return to the normal phase, altcoin will definitely increase again.
No, I do not think that the altcoins will recover. It will be difficult to return to the previous prices. For example, a few months ago ETH cost about 0.08 BTC, now ETH is equal to 0.034 BTC. Moreover, Ethereum has infinite inflation, i.e. miners will always receive the new mined ETH coins and will sell them on crypto exchange markets. Perhaps other altcoins have the opportunity to grow.
Bitcoin really shows resilience. HODLERS do not sell their BTC, so Bitcoin remains strong and does not drop below $6000.