I doubt that they reverted to the previous code (if that was even possible) as it would be setting them up to fail in the future if the popularity of BBO exploded. We saw in March 2019 that you may only get two weeks notice ... assuming you recognise the notice.
hrothgar, on 2021-August-24, 11:42, said:
I suspect that it means that they fixed the file descriptor limit
I agree that the code was probably full of 16-bit values (where the maximum would be 65,535) and it needed to be upgraded. In my distant past I used to port code between platforms and such a task would be a nightmare, in terms of the rigour needed to catch all the explicit and implicit dependencies, which is probably why it took so long. If only you could say, "change all 16-bit integers to 32-bit integers" and it worked