None of the exit polling done anywhere, anytime, for any election is that good and certainly is never evidence that the voter numbers are wrong.
I'm not talking about "this year's primaries." I'm talking all primaries, elections, etc for every year ever.
And yes, they already get disclaimers.
That's not to say there's no value in them. People use exit polling and demographic data to make election calls earlier than the total votes are counted. You can also get a sense of what people think about, like when they ask "what was your top issue" or try to figure out roughly what % of people voted in this age group, race, ethnicity, gender, etc. It's not close to perfect and should be understood as such.