It totally depends on what we mean by ''most/least extroverted''
ESTPs tend to have the biggest social network of everyone I know and they also tend to be on the loud and energetic side. So in that sense they would qualify as the most extroverted.
ExFJs come in second for obvious reasons.
ESFPs very popular yes, but I think Fi tends to be more ''pick and choose'' who they interact with, so I disagree with them often being ranked number 1.
ExTJs come next
Then ENxPs with their notorious ''Most introverted extroverts'' reputation which I tend to agree with.
IxFJs vice-versa from ENxPs
ISFP and INFPs typically have this mysterious loner, artist persona attached to them, but I think as feelers, they crave interaction on some level. No point being a free-spirit if nobody cares/notices. Which I always thought was a bit of a conundrum.
So that un-surprisingly leaves IxTx types, but which is the least extroverted is hard to tell.
I think we can chalk up ISTJs first for the simple fact that they are in tuned with every reality and life but moreso because they are often bound to social obligations and may find themselves constantly surrounded by people or doing typical ''extrovert'' activities whether they want to or not. My brothers are ISTJs too and I legit don't think they ever spent a day alone in their lives. The need for other people at this point is probably very ingrained in their dominant Si and I see this for many other ISTJs. Albeit I think it's because the last generation of ISTJs were drilled to have families and be community-oriented people, so that might dissapear with time. For me personally, I try to avoid social interactions like the plague, but yeah, I'm constantly bombarded with invites for this and that, many of which are mandatory (at least from a Si/Te perspective). I just don't see other IxTx types having to deal with that shit on a daily basis.
ISTPs have Se so they too interact heavily with immediate reality. I think despite their portrayal of being badass loners in movies, in real life they tend to be quite popular and love to have fun with other people (They are very close to ESTPs after all).
INTPs are known for loving debates sharing wacky ideas and memes, but yeah they definitely have that socially-awkward, independent thinker stereotype which I think is based on some truths. In any case, I would expect them to be more disconnected and hermit-like than ISTx types.
So finally INTJs. Problem is, I never met one in real life so I might be talking out of my ass, but functional wise, it would totally make sense for them to the most disconnect type from the environment and other people. Hell, the ONE reason I wanted to type myself as INTJ initially was not even for the super awesome prescient/genius/inventor/philosopher/mastermind portrayal they always receive online, but for their notorious misanthropic tendencies they are always described as which I totally relate to.