So, how was your IT department treating them at time time?
As valued employees, pairing with the Java devs on code, attending team lunches and other functions, generally integrated with the teams to which they were passing on their life's work?
Because to be honest I'm struggling to believe they were being treated as equal members of a team if they were behaving like that.
I think the statement "convinced to stay until migration was finalised" already answers your question. I'm sure there would be some that would have wanted to, and been capable of, picking up a different language, but that is not how companies do things. It's replace with the new, even though a lot of business/application knowledge could be retained otherwise.
I think the (governmental) department treated them alright, and they made good money too. They were not the types that liked to blend with the younger devs, even for a cup of coffee. I approached them two years ago and asked if I could work with them for some time to exchange knowledge, but I only got a one line email response "not interested". It's not unlikely that they were annoyed that the applications they had developed over the years, which they kept pointing out were superior, were being phased out.
As valued employees, pairing with the Java devs on code, attending team lunches and other functions, generally integrated with the teams to which they were passing on their life's work?
Because to be honest I'm struggling to believe they were being treated as equal members of a team if they were behaving like that.