There are many bytes on the internet explaining why you should or should not use so-called "Vanilla Fantasy" for an OSR game. I'm here to do my part in the fantasy discourse.
Vanilla fantasy, for those unfamiliar, is what people think of when they think "fantasy" - goblins, dwarves, dragons, elves, et cetera. The common rejection of this is usually personal sentiment, generally in the realm of "it's boring." This can come from either players or game runners; however I think both can be invalid.
I think the existence of vanilla or non-vanilla elements is orthogonal to the actual gameplay - especially in OSR. More simply, flavor rarely brings any interesting gameplay decisions to a game. If you're playing OSR, the resource management or deadliness can always be mapped directly to an analogous vanilla element. More snidely put, flavor is free and you get what you pay for.
On the other hand, I think being creative in design is wonderful. Non-vanilla elements get the mind going and give more prompts to work with. It also helps keep the dungeon unpredictable, which is always a good thing. And it might help slightly reluctant players to get on board with the implied setting, before they would get into the gameplay mindset you're trying to cultivate.
So yes, vanilla gets the job done, but changing things up a bit will bring some extra excitement.