Nope. They're read out by a short description like "slightly smiling face" or "crying face" or whatever. Currently, IOS, OS X, and Android fully support them. But windows is a little behind. If you're using Windows 10 and the new Microsoft OneCore voices, than they work. Otherwise, they don't.

Depends on the screen reader and synthesizer combination how they are read. Sometimes they can be annoying, especially when they have skin tone modifiers and they are read, so something like slightly smiling face, light skin tone. What is super annoying to the nth power and gets me raging every single time is when people use 10 or 15 of them in a row, often the same one to emphasyze. Another utterly annoying use of them is the clapping hands emoji to split words.

It's only really annoying if people spam dozens of them. I think emojis (In my day we called them smilies or emoticons) should be used sparingly, perhaps one at the end of a sentence like a punctuation mark. Of course this isn't a blind only issue.

All emojis are actually accurately described when encountering one with a screen reader. iOS well interpret smilies typed in chat, and all mobile and desktop screen readers will announce emojis. I do hate it when designers get lazy and start adding emojis all over their websites, especially in front of links when the emoji makes no sense in the context of the link. InstaCart, for example, uses a bunch of random ones all over the support page on their site. What does a fork and knife have to do with my orders? I'm sure they look pretty, but need to be used sparingly or properly in design. Use in messages is totally fine. "

I find Imojis to be fine. I don't use them alot myself and if I do it's mostly :) :( and : P

I don't come across them that much on websites.

There is an addon that enables them with NVDA as well, even without the windows core voices. Check the addon repository. You can even add your own, if you so choose.

They piss me off. I can't see well enough to tell what the hell they're supposed to be. I disable them whenever possible.