At the time, the studio president said that there were no plans for a Marvel R-rated ,but it seems his stance may have softened a bit.
Over the span of a few weeks in the spring of 2013, Marvel re-acquired the rights to Blade, Ghost Rider, Daredevil and The Punisher.
When I started at Marvel 17 years ago, the Blade franchise was doing very well.
With Marvel’s Phase 3 slate already planned out, coming to a close with Avengers 4 in May 2019, it’s possible that Marvel Phase 4 could bring the first R-rated MCU movie.