with crisis over and one earth, it's like the timeline has been reset again similar to flashpoint.
barry no longer says "I'm the fastest man alive" during the shows intro...this opens possiblities of wally becoming faster or other speedsters coming in that are faster than barry, like godspeed.
this would also cover up all the inconsistencies and hiccups the writers have made over the years regarding how fast barry is, and about the speedforce, ect.
i don't care if they sign alegra or chester as regulars as long as it doesn't affect the special effects budget and holds back the show.
just so others are aware in season 4 when barry is training cisco and caitlyn and taking them into speedforce time, barry says he goes mach 3 to tap into speedforce time, he does this effortlessly, so obviously when he came out of the speedforce he must of been significantly faster than wally, reverse flash, ect as they all commented no speedster had ever gone that fast in season 4 ep 1.
nothing much has been confirmed if barry is faster now than before crisis, meaning even though spectre unlocked barry's potential we don't know if it was temporary or permanent, he may of been able to tap into this potential briefly to do what spectre needed him to do.
what we do know is when barry first encountered alegra and her sister, barry could not outrun the ultra violet rays, and guideon confirms that light travels multiple times faster than his top speed, therefore barry at that point couldn't run at the speed of light and was quite abit slower than the speed of light....the other thing too is when barry runs he speed is probably not always constant, meaning you can't use point A to B and say this is how fast he's going because he can accelerate or de-accelerate at will, wants to run at mach 3 for so many miles then slow it down to mach 1 for so many miles you'd never get an definitive speed vs time result unless he went full out from a starting point to a finish without slowing down.