Riot: Grow the Challenger scene by offering them professional scrim partners.
The EU LCS Promotion Tournament showed that the Challenger scene has a lot of disadvantages compared to the LCS teams they're required to beat in order to qualify. Last year, the only really convincing move up from Challenger was Origen, a team built by seasoned professionals who were re-qualifying. The teams attempting to make the step up to LCS caliber have a giant hurdle to overcome just trying to get the practice they need to improve.
On the other hand, you have players who still have the skill to be professional players, but lack the opportunity (a parent, for example) or motivation to become one. Players who have retired from professional play but still maintain a professional level of play are still out there, streaming and enjoying the game.
With the kind of sponsorship and investment teams are starting to see, wouldn't it be worthwhile to invest in offering professional-level scrim opportunities to Challenger teams that would otherwise not have the opportunity to get adequate practice? Contracted, reliable, highly skilled players could easily be coordinated by someone with even a modicum of project management experience, ensuring efficient scrims and even opportunities for analysis to rising teams. This way you're not shutting out competition, you're supporting and nurturing new talent, etc.
Compared to what your overall LCS budget must be I can't see this being unfeasible. I'm not saying that you should do this - I haven't exactly done a cost-benefit analysis on this. (Though if I did, I'd probably look into per-game rates for high-level players, with an amount to be at least comparative to successful streaming revenues in order to ensure they're not working at a loss.) However, it would certainly be worth looking into. And if it wasn't run by Riot, this could potentially be an opportunity for private investment to grow the scene.
Think about it, get back to me. Your people can contact my people and we'll do lunch or something (the 'or something' is code for 'chicken and red velvet waffles').