Importing language A>B and B>A tmx into a new A>B TM: are they both imported?

Hi,
I am currently in the process of trying to consolidate years of TMs (many intersect, there are plenty reps, etc.)
There are literally all sorts, some in En (UK+US)>Fr, some in Fr>En (UK+US) and some anyTMs.
I have first exported all of them as tmx, then consolidated them back into newly created themed TMs. So far so good.
My question is the following:
When creating a new TM, it is one sided (i.e., language A > Language B, not anyTM.)
When I import Fr>En and En>Fr tmx (both UK and US) – and they do all import fine, or in any case I received no error message – are all types imported into the new TM? Or only the types whose language combination is identical to the newly created TM?
I'd like to confirm everything has been properly imported before getting rid of any of the original TMs...