I do use the android version available on fire tv. If they don't have much more live cycling I can always check kodi....It's been around for a long time and is kind of hit or miss. Just like NBCSN in general. It's not a very well regarded app on the Android side but it does work for me. I can even cast it to my TV even thought the app doesn't natively support it. PQ is pretty good. What's odd to me about the rebroadcasts is that they are not the same ones that aired. Different commentators and program lengths. That can be good or bad depending on your point of view. For example years back many Olympic replays were completely devoid of any commentary. Odd, and rather useless for the Olympics where many sports are uncommon to many viewers.
As to what will be on in the future it's hard to tell because the search features are pretty bad (at least for the Android one). It seems like they mainly just stream stuff that was on air anyway so as far as many of the spring classics and grand tours other than the TDF you will be looking elsewhere. My recollection is that the TDF has always been a pay per view (or pay for all) style offering rather than free streaming or replays. Even to cable subscribers. But since they basically broadcast on air all July from the TDF and I can DVR to my hearts content that's OK with me.
The only reason I reinstalled it recently was because NBCSN had every day of Paris Nice on their on air schedule except the final day. So I was prepared to stream it. At the last minute they aired Sunday's stage live. It never actually appeared on their schedule though. So just remember who's behind the app and how unpredictable they are. But, oddly this year every single publicly scheduled Paris Nice stage actually started on time at like 1 or 2 am rather than being overrun by some mindless re-hash talk show ! So hell has surely frozen over and things may be looking up for NBCSN