And don't forget that ESA "owes" NASA for the Beagle II search
A LOT of spacecraft time was given to ESA to search for signs of it's lost Beagle II probe (time which would have been better spent on other things, and unneccesary if Beagle II had been designed with proper EDL telemetry - a lesson NASA learned earlier). it's only "fair" that ESA now make some efforts to assist NASA, and avoid the risk of an unobserved entry.
Clearly, nobody EXPECTS to lose a lander, but IF it is lost, it is important to learn from that, hence the need to both transmit and receive the EDL telemetry...