There are a handful of factors that play a role in canonicalization: […], and rel=“canonical”link annotations.
(but Google considers it a hint, so they don’t have to honor it)
Also, that change was just for Lemmy. Other Fediverse sites may not do the same, which would lessen the effect. For example, from a quick look at a random federated post on kbin.social, there was no such <link rel=“canonical”/> element present in the page source.