They kinda do rhyme with the right enunciation. How is that bad poetry or cheating? Language is complex and bending how you say things is part of good rhyme. I imagine historical linguists are very familiar with this and factor it into their work.
Which is a somewhat more positive way of saying that they rhyme with the wrong enunciation. Which is a totally valid way to construct lyrics in music - you have a bit of artistic leeway and the exact "correct" pronunciation isn't exactly important - but it's probably not too helpful for a listener who's trying to work out how those words were actually spoken in conversation.
That said, I'd be far more concerned about a future linguist discovering Prisencolinensinainciusol.
Greek has Demotic and Katharevousa. Louis de Bernieres writes in "Captain Correli's mandolin" implying that the English officers in ww2 sounded to the Greek peasantry like Shakespearean actors, all taught Greek in boarding school, but only speaking "high" Katharevousa Greek, not the common Demotic. He does this by using archaic English writing.
English code switching .. is that really that different yo? Yeet me out of here. Valley girl speak.. the list of dialect and pronunciation in contemporary US culture of the last 50 years is immense.
I bet that without a relatively large amount of exposure they can’t and then suddenly it’s really obvious what the other person is saying. That’s my experience listening to Nigerian English. Didn’t realise the guy working next to me was speaking English with his compatriot for two weeks and then suddenly I understood. Written Portuguese and Spanish are very similar, like Norwegian and Danish levels of similar, or Scots and English.
There are lots of different dialects and accents in the UK, let alone the US. AAVE for example is as legitimate a dialect of English as General American. Bush, Trump and Sanders all speak "American English" yet they sound very different because of their regional accents even before you get into personal quirks.
There's no singular "correct" pronunciation today and there certainly wasn't one in medieval England. We just have "standard" pronunciations based on a rough approximation to one arbitrary dialect we decided to treat as the reference point.
Yes there is. If a linguist a century from now claims that English speakers in 2021 pronounced "car" the same way they pronounced "book", they would be wrong.
Similarly, if they looked at one 2chainz song and concluded that in spoken word "pyjama" and "lasagna" rhymed, that would be wrong. Less obviously so, but wrong nonetheless.
The absence of a singular correct pronunciation doesn't diminish the infinite number of incorrect ones. Even the most ardent of descriptivists think that accepting a pronunciation based off of a single occurrence is somewhat taking the piss.