That's kind of a silly "fix", if I saw that as the present time, I would've simply thought that the time circuits were malfunctioning. And actually, that might be the case here too, I remember when there was issues with the time circuit display when our ride was open.
A better fix, IMO, would've been to digitally alter the footage to say 2050 or 3015, as well as any audio references to 2015. They've altered the footage before to add in any new sponsorships, like Toyota.
I mean, technically, if after 2015 the ride is still open, it still makes sense calling it Back To The Future. It's just that every scene will be the "past", and then we go back to the future at the end, which is our present.