A year ago I made a small patch to the following mod to work with the Redux classes:

Lyrae's Expanded Callsigns and Nicknames
https://steamcommunity.com/sharedfiles/filedetails/?id=1129464749&tscn=1552680710

This was a result of that creator refusing to engage with the community. The actual variety is good, although parts of it have been copied from an earlier XCOM EU mod.

...

Anyway, to work with Richard's Classes, navigate to:
\Steam\steamapps\workshop\content\268500\1129464749\Localization

Open the file 'XcomGame.int' with notepad.

Underneath all entries, simply paste the support text from my pastebin and save the file. This duplicates her existing nicknames for the new custom classes.

https://pastebin.com/x3PYMv8W

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... or you know, perhaps Richard may adopt the nicknames at some point with assumed permission, since the publisher is unreachable?
(I understand if you do not want to, I have been considering publishing a master version of her mod which works with every class mod known, since it's just a basic .ini splice into the class templates.)