Tell us about the floor. Wood sheathing over crawl space? Over basement? Floor is concrete slab? And how far from the heater to an outside wall?

The answer to your question is "Maybe", and it would require approval from your local inspector.

If your tub waste & overflow is the glued in type that is considered permanent plumbing and they may approve that if you install the tee, then make a vertical riser so the lowest end of the pan drain is a minimum of 2" higher than the flood level rim of the tub, but if it is a slip joint tubular type waste & overflow, that is considered a temporary connection and you cannot insure that the pan drain would be connected if someone had to change it out in furture so I doubt if they would approve it.

The more important code question is, where is the water heaters T&P line terminated? Code prohibits terminating the T&P into the pan. The T&P must also have a full bore line running by gravity flow to the exterior of the structure or to a clearly visible indirect waste receptor, however, in instances where you cannot achieve a gravity flow line, such as when a water heater is installed in a basement and it is below the house sewer, there is another option for the T&P.

The T&P line can be removed and the port plugged, then you go to any convenient point on the hot water system where you can achiece a gravity flow drain either outdoors or to a utility sink or floor drain, you can install a "Pressure Relief Valve".

You may discuss both of those options to your inspector and if luck is with you, you may get approval, but don't be surprised if they tell you to move the water heater to a more suitable location.

This is in a mid-rise condo with poured concrete floors.
But, nevermind, the water heater is going into the laundry closet.
The washing machine drain will become an indirect waste receptor - 3" to 1.5" reducer should do the job nicely.