As we know... The franchise had started to move it's attention from Brian to Dom anyway so continuing on that would not be difficult. If you watch back too, Brian was struggling with choosing between the 'fast' life and the Family life since Fast Five so it's not that strange that he ain't there anymore.
There are also more characters to focus on now than ever befoThere are also more characters to focus on now than ever before (Hobbs, Monica Fuentes, Mr Nobody, Shaw Brothers...) that can easily help lead the franchise.
There are story lines still to explore too like Leon, Tokyo Drift and the Prince in Abu Dhabi who probably wouldn't take too kindly to having his penthouse and £3.5million car trashed!!
either way, I think the cast and crew have enough love for Paul to keep the franchise respectful to him!