The caveat is, for major/critical or gamebreaking bugs they can be asked by the developers to gather information.
The problem is that posters come here and declare a cosmetic colour or shoulders ‘floating’ as being ‘gamebreaking’ and want it to be escalated in a Priority 1 Bugfix as an example.
Generally however most bugs should be reported through the ingame button as that also attaches a lot of internal info besides the box you fill in or on the US bug report forums as advised by our resident Blizzardian here: