The GP on twitter was laid off almost two months, and not given their severance as far as we can tell, or given any notification of severance.

More or less they were fired on the spot, and they'd have to find some legal means to recoup any backpay / severance from Twitter (Musk).

In OP's words, they're the landlord who did not get paid and the tenant (Musk / Twitter) is abusing their power.