There's a letter from Stellantis on the IATF website
here.
View attachment 27819
I would continue to use whatever CSR's have been agreed with your customer unless told otherwise. It sounds like they're deciding on how their CSR's will work following the merger. Talk to your contacts and see what they have to say, it could be a while before new CSR's turn up.
Mind you I'm still waiting on JLR's CSR's...