My guess is, it's because in the beginning of the pandemic many people started reconnecting with people they hadn't talked to in a long time, and some suicidal people found sympathetic ears.

Fascinatingly, social media and messenger apps probably have data to back my guess, "Of people that interacted with each other, give me the time interval since their last interaction", and my guess is, the average of that interval would've increased in March/April 2020.