Grinding 3 legendary (anything) zero moonstones

How long have we been able to use the grinder with three weapons, grenade mods, CoMs, ect. that are all legendary? It also doesn’t take moonstones and so far every time I have gotten a legendary.

Is this some sort of glitch, or have I never known?

No glitch. That’s always been the case. What 2KAus/GBX did add was the ability to grind 3 purples for a chance at a legendary.

Thank you @BookEmDano! I just never knew I guess.