I recently finished my Tommy John surgery research and found myself chronologically at the earliest documented surgery. Tommy John, the player, came up as the final (or first) record and as I entered the comment into his transactions history, I questioned to myself whether I could actually write, logically, that Tommy John had Tommy John surgery ... but I did anyways.
The Transactions section of players pages now show "Tommy John Surgery" or "Recovery from Tommy John Surgery" where the player is known to have had the surgery. The Transactions section theoretically goes back in full to 2012 but I have bypassed that restriction for TJ surgery and all known players to have the surgery prior to 2012 also have a record along with the (approximate) date of the surgery. The date are erratic though because I don't have documentation. For more recent players, the date is not actually the surgery itself. It is the date placed on Injured/Disabled list. For some players, the date is listed as 1/1/YYYY which indicates we only know the year of the surgery. There is ample use of the data for analysis but recovery time might not be a great indicator since the recovery the surgery only starts once the surgery has occured and without that date, the analysis is invalid. However, the opportunity to analyze statistics pre and post surgery remains.
Is the list complete? For Major Leaguers, likely. For Minor Leaguers, likely not but fairly decent. For College players, no sir. I am aware that Tommy John surgery occurs earlier and earlier in a player's career and though I do have captured records for players getting the surgery in High School or College, these players went on to have a professional career. If Steve Jones had TJ surgery in high school but was never drafted and never fully recovered from the surgery, it won't be in our database.
The new PREMIUM site will have a way to isolate all the Tommy John surgeries and we will be developing a report which will include raw data for analysis for all TJ players.