Easy to reproduce, simply go to the nether, find a fortress, and find a blaze spawn platform- no spawners.
Chests are clearly absent as well after checking multiple fortresses.

Blaze pillars and bastions generate spawners and chests correctly and consistently, issue is unique to nether fortresses

Oh god this is really funky, I'll investigate when i can

Additional information from 1.3
Issue extends to desert temples, no chests.
Chests (both vanilla and modded variants), and spawners seem to be generating correctly in lost cities, stray towers, battle towers, shipwrecks, zombie villages and ruined portals.

Re-tested in 1.3.1
Chests/spawners are present at shipwrecks, buried treasure, dungeons, apotheosis cave and boss spawners, igloos, battle towers, warped gardens, dragon nests, lost cities, cyclops caves, ancient leviathans, blaze pillars, bastion remnants

Chests, dispensers and spawners are NOT generating in desert temples, jungle temples, or nether fortresses.

Issue corrected in 1.3.3, closing the thread!