I think Tyson was keeping in shape for his TV programme about Sharks and during the lockdown rumours have spread he will fight Holyfield/Briggs/Fury, get into MMA/UFC etc

Tyson has probably allowed these rumours and videos to be circulated. Some of it has gained traction but I think he will not risk losing his dignity by getting beat up even in an exhibition. It would harm his reputation and future earning potential as well.