They reaffirmed their commitment to staying free just this week, so I believe at least for the time being we should be fine… https://blog.cloudflare.com/cloudflares-commitment-to-free/
Cloudflare BlogReaffirming our commitment to freeWe want to make abundantly clear: our free plan is here to stay, and we reaffirmed that commitment this week with 15 releases across our product portfolio that make the Free plan even better.
I was actually thinking about this the other day in relation to @cloudflare I really hope they stay the course. They’re an awesome group of people!