Wait wait I might actually have an answer
Tolkien wrote The Hobbit like waaaay before he even dreamed up the idea for Lord of the Rings, so when he DID dream up LotR, he had a whole bunch of stuff that didn’t make sense. Like plotholes galore
Like for example in the first version Gollum was a pretty nice dude who lost the riddle contest graciously and gave Bilbo the ring as a legit present and was very helpful and it was super nice and polite and absolutely nobody tried to eat anyone because this is a story for kids and that’s very rude
But that doesn’t work with LotR, so Tolkien went back and re-released an updated version of The Hobbit with all the lore changes and stuff to fix everything that didn’t work
This is the version we know and love today
BUT rather than pretend the early version never existed, Tolkien went and worked the retcon into the lore
If you pay attention in Fellowship, there’s a bit where Gandalf is telling Frodo about the ring and he mentions how Bilbo wasn’t entirely honest about the manner in which it was found
To us modern readers, this doesn’t make a ton of sense, so mostly we just breeze by it–but actually that line is referencing the first version of The Hobbit
The pre-retcon version of the Hobbit is canonically Bilbo’s original book. The original version with Nice Gollum is canonically a lie Bilbo told to legitimize his claim to the ring and absolve him of the guilt he feels for his rather shady behavior
Then the post-retcon version is an in-universe edited edition someone went and released later to straighten out Bilbo’s lies
So it’s 100% plausible that the in-universe editor who fixed up Bilbo’s Red Book and translated it from whatever language Hobbits speak was a human who knew about Christmas Trees and tossed the detail in to make human readers feel more at home, because that’s the kind of thing that sometimes happens when you have a translator editor person dressing up a story for an audience that doesn’t know the exact cultural context in which the original story was written
Tolkien was a medieval scholar and medieval stories are rife with that sort of thing, so like… yeah
There’s a good chance it maybe did cross his mind
