They announced long ago that paid DLC will be a thing, but they’ll be in addition to world updates and sim updates, which will always be free.
An example they provided is a number of additional flyable helicopter when helicopters become flyable (IE: you won’t need to pay for the DLC to fly helicopters, just to have more). This was said in the very first Q&A after release.
Incidentally.
You should not make this kind of assumption. It’s most definitely based on nothing.