A true "squeeze" happens much faster, almost like a crash in reverse. On the order of a few days at most you would see sharp spikes in price, causing an avalanche of margin calls leading to forced covering at any price. As such, any pressure playing out on shorts over a longer period of time is going to be more of a slow bleed, as shorts are slowly forced out. At the same time, more shorts can more easily be persuaded to enter the market due to the lack of extreme volatility makes trying to short the top of a squeeze similar to try to "catch the falling knife" in a crash.
Whether or not it's safer is a relative term. As Buffet says about being long, if you buy at a lower price in a good company then you have more of a buffer. Likewise, if you short higher in a bad company you also have more of a buffer, but by nature shorting is a much riskier proposition even in the best case.
By the way, on a longer time frame like months that we are talking about, you have a better opportunity to test your hypothesis that "most shorts have been covered" by checking changes in short interest over that time frame.