This article seems to be discussing loss of taste and smell, not distorted taste & smell.
The article I posted was a press release, based on this scientific article, which I just glanced through.
https://onlinelibrary.wiley.com/doi/full/10.1111/joim.13209They wanted to figure out the prevalence of olfactory dysfunction, and how long it lasts. They did include different types of dysfunction, but it looks to me like there's overlap between their categories. They include anosmia (no smell) and hyposmia (reduced smell). "Dysgeusia, defined as the impairment of salty, sweet, bitter and sour", cacosmia (sensation of a bad smell), phantosmia (perception of a smell when none is present) and distortion (can't tell if this is a new category or includes some of the others).
I don't see anywhere that they analyzed how long it takes for recovery from each type of dysfunction, but overall, it's reassuring that 95% recovered by 6 months. They looked only at 2 months and 6 months, so many of those recovered in less than 6 months.