2013 is not too old. Those books are absolutely fine.
Nothing has changed since then. The learning objectives are still the same. 90% of the exam questions are still the same
Aerodynamics are Aerodynamics. A piston engine still obeys the same laws. Hell, even airlaw does not change. This is high school level stuff - It's just a lot.
Don't worry about it. The only differences between these yearly revisions are basically spelling, grammar, and the occasional image/graph. You won't miss out on anything by using an older book.
--- /incoming personal rant
Self published books, in an academic/scientific context, written by your own teachers, are worthless.
There are no authorities in science. You are judged on the merits of your arguments. Nobody knows everything, nobody has up-to-date knowledge on everything. Nobody has time for that. That's why we let the academic community/market forces decide on what's good teaching material and what's not.
So I seriously doubt you attended a top uni, or majored in anything scientific or otherwise in constant flux.
There is a reason you won't find many french universities in the yearly top 100 rankings.
Note that I am not saying a 300€ book is inherently better than a 50€ book. I'm also not saying government funded universities or books are bad.
/end rant. I get seriously triggered by this nonsense.