If you look at the percentage of affected reviews [1], it looks like some customers might be experiencing long term loss of smell. Note how the percentage of affected customers is still considerably higher in mid 2021 (where covid numbers were pretty low) compared to January 2020.

The graphs are based on only about 150 negative reviews though, so I don't know how much you can read into it.

[1]: https://twitter.com/nick_beauchamp/status/147355576211076710...