I think that's totally plausible! Especially because the fact is that "intelligence" is an incredibly fuzzy concept, such that one could be extremely intelligent in the STEM fields, as you mention, but then be simply average in linguistic ability.
Accordingly, even IF the willingness and ability to use profanity indicated a lesser linguistic intelligence, one would be mistaken to then assume that a person with that willingness is any less of a capable professional in non-linguistic fields
You should really read the literature you try to post. From the abstract of the study the article cites (~and the article itself implies agreement with~):
"Overall the findings suggest that, with the exception of female-sex-related slurs, taboo expressives and general pejoratives comprise the core of the category of taboo words while slurs tend to occupy the periphery, *and the ability to generate taboo language is not an index of overall language poverty.*" [* Emphasis mine]
Edit: realized the article does make the distinction between the ability to generate profanity and the willingness to do so, which while interesting is mere conjecture propped up by an anecdote within the article. I contend there are times for profanity and times for avoiding it, but suggesting that because someone chooses profanity they must be less intelligent is perhaps a comfortable idea, but it may also be an elitist one.
The cynic in me supposes that's because they have backdoor access to LastPass and not to bitwarden. Actually, LastPass keeps getting hacked so I just about expect it to be the case.
Accordingly, even IF the willingness and ability to use profanity indicated a lesser linguistic intelligence, one would be mistaken to then assume that a person with that willingness is any less of a capable professional in non-linguistic fields