Can't answer for the Team, but right now you cannot, not sure if there are plans to change it, but uservoice feedback or feedback in general on here is welcome.
It's more a habit change that I'm getting people to do here at the office using "Tentative" status for their self block items. If your Out of Office then you should really be Out of Office so not sure why people even use that option anymore specially with the way most places have remote employee's these days. If you don't want to be out of office, don't use out of office meeting block or don't set your auto response that your out. It would be nice if you could override the option thou temporarily, then switch it back to Out of Office. My guess these changes will come, this is first iteration and although has a few quirks it's light years better than what we as Teams users have been dealing with the past year+ with presence.