Having, or not having, braced longbow visual tip reflex is only an aesthetic thing, no more or less.
IF a braced longbow exhibits ANY amount of "flip to the tips" it ain't a "D" shape R/D longbow. This is mostly a very visual thing as most mild R/D longbows still show some amount of tip reflex when braced. If it matters, and yer not sure, use a small straight edge to check a braced bows tips on its back and belly.
Again, it's just an AESTHETIC thing.