Are you referring to historical (actual) stats, or stats that are generated from playing out OOTP?
Since you referenced 1915, I assume you mean stats from playing out OOTP, since 1915 - well, actually 1914 (the OOTP panel is mislabeled) - is when OOTP introduces his historical minors in the form of the Federal League (which was actually a major league, but that's another subject).
Assuming so, then OOTP does not specifically generate stats for minor leaguers. However, depending upon your settings - namely, if you have historical minor leagues enabled, then even though there are no minor leagues in, say, 1910 OOTP minor league players will be included. And so - again, depending upon your settings - major league teams may sign some of the better minor leaguers. And they would play and generate stats; though not minor league stats.
If you create minor leagues and minor league teams, then those teams will sign minor leaguers and they will play and generate stats.
If, however, you play with a setup where there are no minor league teams for historical minor leaguers to play on or otherwise prevent minor leaguers from signing with MLB teams, (and for any minor leaguers in the scenarios above who aren't good enough play on major or minor league teams), those players will exist but they won't play games and therefore won't generate stats... At some point they will retire.
Hope this answers your questions... and makes sense
