[orbifold]

I associate and would use Yay only as an ironic expressions of excitement, as in "Two more weeks of working overtime, yay", but I have only found a discussion in an catholic forum as evidence that some people think the same way.

I don't believe I have ever heard someone use "Yay" in a non ironic fashion, but I'm not from an english speaking country.

So you could easily imagine a situation where posts by popular kids would get likes but posts by outsiders only yays.

[davnicwil]

English-speaker here (UK) - just to let you know that Yay! is very definitely used in a non-ironic fashion all the time as a light-hearted, perhaps slightly jokey, expression of delight. In text, and sometimes even in speech.

I can 'calibrate' a Yay to indicate a negative sentiment based on context, but it's a bit jarring and not even very strongly negative. Examples like "Two more weeks of working overtime. Yay" is obviously a negative use but, to me, that's you indicating disapproval of a fairly trivial inconvenience or annoyance in a rather light-hearted way. If you really disliked something I'd expect a more direct statement like 'damn it' or your whatever your chosen flavour of profanity.

The idea of Yay as a general meme for negativity is very jarring, at least to this native reader, and I'd really struggle to imagine it ever catching on as a result. Hope you found this perspective useful!