I have a 2021 GLE450 with leather seats. My understanding is that newer vehicles have leather with a light coating on the surface, ie: it is not raw leather.
I put a drop of water on the seat, it beads and sits there, does not get absorbed into the seat.
I scratch the leather with my fingernail, no change in color.

Can anyone confirm that these seats are indeed "coated"?

If the vehicle does indeed have a "coated" leather, is there any use for conditioning of the seats? Or just wipe them down once in a while with damp microfiber (+/- drop of soap if actually cleaning up a mess), and then protect with something like 303 Aerospace?

Any suggestions would be appreciated.

most car leather is coated with a clear vinyl like substance to protect them from stains and water etc.
Still use leather conditioners versus 303 type stuff - better over all for seat.

leave 303 for plastics and rubber IMHO

There are some leathers used that are uncoated but tend to be the most expensive sea material option.

You did right by tsting with drop of water first as nothing worse then water spot on a leather and you have to wait for it to dry and then condition entire surface to make look right again.

All car leather for the past 20 years has been urethane coated. No “conditioner” or “nourishment” or “moisturizer” will have any effect. Except maybe a placebo effect.

Clean the leather with a damp (water) cotton terry cloth.