If there are two players or doubles teams from the same country, they will be drawn in opposite halves of the draw.
If there are three or more players/teams from the same country, they will be drawn in different quarters of the draw.
I don't see anything problematic about it.
All draws are already being 'fixed' by the 'seeding'. Meaning, you just place seeds #1 and #2 on the opposite sides, then you draw #3 and #4 in such a way they can't be in the same half, and then you draw #5, #6, #7, #8 each in one of the quarters etc. So, the draw is already 'fixed' - i.e. it is not *completely* random. This stuff above only adds further non-randomness; and since Olympics are based on the concept of 'nations', this looks like a good idea to me. It will still be pretty random as a whole, just not as random as usual tennis tournaments.
Why are you so shocked about it, actually?