Yes, Trans pan gaskets are supposedly reusable on the newer cars. I
bought one a new one for my 05 Buick just in case I break it removing
the pan in a couple weeks. There are steel washers that the bolts pass
through to prevent the gasket from getting crushed down.
Some people have had good luck without servicng a transmission, others
have not. You have to decide what you want to do for YOUR car.
I've changed trans oil about every 50 to 60,000 miles on my Bonneville
and I got 192,000 out of it before it began to slip.
A friend with a 92 Corolla changed his every year / 30,000 miles and got
253,000 miles on it when the trans died .
I'll change the trans oil on the Buick this month sometime, technically
the car is now two years old, only its one year old to me.
05 Park Avenue 37,809
91 Bonneville 306,528