yes it can, it has happened before back in 2017 and i believe we'll experience the bullish run again soon
History might happen again and just like that ending of that year. But, be open-minded that it could also be not. Many altcoins can go into bearish while some biggest altcoins can do bullish which is the opposite of the forgotten altcoins.
Of course you can but not all altcoins will be bullish together, only top altcoins can do that. For new altcoin it still requires a very long time to survive
This is my point.