Jay Jaffe wrote this article I linked below in May on FG that updates the info you posted. 27 pitchers have had TOS since 2001. There's a table that Jaffe references that I can't add due to formatting. Here's an exerpt.
"The count is now up to 27 pitchers, with
Carter Capps,
Luke Hochevar,
Tyson Ross,
Nathan Karns and
Vince Velasquez having followed in Harvey’s wake. (Edwards also seems to have missed counting
Clayton Richard, and we both missed
Nate Adcock,
Daniel Bard,
Mike Foltynewicz and
Nick Tepesch, until readers alerted me.)
Here’s the table, ordered by post-surgery innings (for Hughes and Harrison, the numbers are with respect to their first TOS surgery):
The average total of post-surgery innings for the group is just 218, compared to an average of 657 innings prior. Excluding the three recent pitchers who have yet to return to the majors and the three who never did (Lowry, Rheinecker and Bard), those figures rise to 732 pre-surgery and 281 post-surgery. The relatively heavy post-surgical workloads of Cook and Rogers skew those figures; even excluding the zero-innings guys, the medians are just 595 innings pre-surgery and 134 post-surgery. As many as 13 of the pitchers on the list might still be considered active, though VerHagen is in the minors and Hochevar unsigned, so all of the aforementioned figures could rise with the passage of time.
Given those relatively modest post-surgical innings totals and the performance data, the numbers are rather sobering, and that’s while keeping in mind that pre-surgical performance may have suffered due to the symptoms that led to the diagnoses. Of the 21 pitchers who returned to action, only five lowered their ERAs relative to the league across any sample (Beckett, Cook, Foltynewicz, Harrison, and Richard), and only five did so with respect to FIP (Cook, Foltynewicz, Harrison, Richard, and Velasquez). The ERAs of four other players rose by less than 10% (Garcia, Velasquez, Cobb, and Rogers), with Cobb and Rogers the only two about whom the same can be said with respect to FIP; these pitchers were still quite serviceable if not exactly as effective after the surgery as before, and from that group, all but Rogers are still active, which is to say that they may yet join the first group."
At the other end of the spectrum, 10 of the 21 returnees saw their ERA- rise by more than 20%, and 10 did so with respect to FIP-, including Hughes (an ERA- 29 points higher, a FIP- 34 points higher). Harvey had the largest gains of the group, which is to say the largest fall-off in effectiveness (an ERA- 78 points higher, a FIP- 69 points higher), though at least he’s been trending in the right direction since being traded to the Reds. Ross, who struggled mightily last year, his first since surgery, has been much more effective this year (90 ERA-, 88 FIP-) and might be the strongest candidate to escape this sad group, at least in the near future.
That leaves very few pitchers in the middle ground — namely, the
recently retired Young with respect to ERA-, VerHagen and Wells with respect to FIP-, and Carpenter with respect to both, albeit with just three post-surgical regular-season outings before retirement.
As Edwards noted, there’s no clear pattern here. The strongest correlations I found were between age and post-surgery ERA- (r= -.27) and pre-surgery innings and post-surgery ERA- (r = .21), both of which suggest, unsurprisingly, that younger or more lightly-used pitchers have tended to fare better with recoveries."
https://www.fangraphs.com/blogs/phil-hughes-and-the-sobering-history-of-thoracic-outlet-injuries/