Any device used for collision avoidance will have some of its critical capabilities dependent on both aircraft in a potential collision situation having the same algorithms on board or chaos (or worse) might ensue. Making the update mandatory and taking non-updated units out of service is the only way to ensure safe and reliable performance of the entire system.

You might quibble a bit about the lead time, but updating the firmware is really not very complicated. I tried a different firmware version (or different config file) practically every day at the 15m nationals last year as I was trying to work out a PCAS problem and a interface issue with my LX 9000.. All you need is the firmware and a memory stick.

It's not that hard.

It will all work out in the end.

Remain calm.

9B