That's intentional.
EWOP just makes walking through Platforms cost enemies 1 "unit", just like it costs to walk on a regular road. Without EWOP, it is like 1024 times more costly for an enemy to walk through platforms so it will always stick to roads.
The game now can find paths even if you have no tiles between your base and an enemy.

In other words, it is perfectly fine to put a Base in one corner of the map, a Spawn in the dirrectly opposite corner, and nothing in between. Enemies will prefer to walk through tiles but lack of one won't stop them anymore.