no, they'll just turn it off, in the entire history of geostationary telecom satellites nobody has launched one with enough reserve delta-V/propellant to deorbit itself. To go from a 36,000 x 36,000 km circular orbit to a 36,000 x 250 km orbit (where the atmospheric drag would cause it to reenter) is a LOT of retrograde delta-v required). There's talk of requiring enough reserve propellant to boost to a new 'graveyard' orbit 1000 km beyond geostationary before turning off a satellite, but it's rarely implemented.