There isn't anytime that new projects can't come, be it bull or bear. Although more new projects come to the space during bull. This is because investors believe must project do well during this period. This make them invest more when compare to the bear season.
True, any season of the market the newer projects will come no matter what. But what I have just noticed is that during the 2018 bear market, despite that there were still a few new projects at that time. Majority of the developers have stopped or probably have planned on how they shall enter the market again with their new projects. That was the toughest time for the crypto market because of that bear market, many have quit to invest into the newer projects because they've mostly affected.