Devs Acted Swiftly? A Plague Tale 3 May Already be in the Making
It is possible that the third part of A Plague Tale is already in the pipeline. This is indicated by a job offer made available by Asobo Studio.

Premiere of met with favorable reviews from critics, it also enjoys a large (and very positive) following on Steam. It is very possible that this could have quickly convinced the developers.
Why such a supposition? The official website of Asobo Studio posted a new job offer for the position of Senior Game Designer with a focus specifically on A Plague Tale. As the ad states:
"For a future production, we are looking for a Game Designer to strengthen the team behind A Plague Tale: Requiem from the pre-production phase."
One of the requirements for this position is to have played A Plague Tale: Innocence and/or Requiem and possess experience with action adventure games. So it is very likely that the offer is for something related to these productions, such as an expansion or just a continuation of the latest installment of Amicia and Hugo's adventures. Interestingly, prior to the release of Requiem the creators have posted a similar announcement for the position of animator of a certain project, which ultimately turned out to be the new A Plague Tale.
However, it should be taken with a pinch of salt - it doesn't have to be about another A Plague Tale, it may simply be some game from a related genre.
It seems important to note that the potential employee will "participate in various phases of brainstorming." So whatever Asobo Studio is developing, it is at a very early stage of work.