LOL Notice my name. 

Here's why:Let's say I sign a tenant to a one-year lease, and 3 months in, their personal/professional situation changes, and they break their lease and move out after a 30-day notice (or maybe less).I am required, by law in most areas, to "mitigate my loss" by remarketing the unit, making it rent-ready, and starting up my lead generation machine to get applicants, funnel them into my screening system, identifying good candidates and ultimately leasing them up.

I would not send a pay or quit notice on the 2nd only because your lease has a grace period to the 5th. 

I notice some wholesalers are targeting on-market listings, so why wouldn't/shouldn't a listing agent who is also an investor be able to do the same if they have qualified cash buyers for a occupied rental investment property?

The fact that it happened during Covid was a very unique situation, but you have probably noticed that rates are already recovering if not accelerating.

Has anyone else noticed this?

Are their requirements for what needs to be in a 30-day notice form? 

He would have noticed the water damage at that time throughout the house but chose to not notify anybody.

If you are paying his/her employer, then you need proof they have WC coverage and you need to be an additional insured and be given 30 day notice of cancellation. 

Upon closing you will notify the tenants that they pay you, You can get a lease ready and give the proper notice of new lease.