They may be in negotiations with some patent holder or similar, and just preparing for the possibility that they have to. Adding the strings is a few steps removed from actually removing Rosetta, so the title is misleading.
Apple gains nothing by “pulling the trigger”.
Edit: Here's a related example just from a few days ago for you:
https://arstechnica.com/tech-policy/2021/03/intel-hit-with-2...