Not a remake, not a reboot, but a continuation: Cynthia Dale is back, playing the same character she played when the show went off the air 25 years ago.
Is this the longest hiatus for a live-action TV series?
Not sure, but 25 years ties it with Twin Peaks, if you include the movie. But given how freaking weird The Return was, it's kinda hard to say that it's anything more than an expensive fanfic starring almost all of the original actors and with the same writers and director. Sometimes a director gets enough of a reputation that no one can tell him "no". There were some scenes that were real gems -- almost anything with Dougie Jones -- but there was also 3 minutes of a guy sweeping a large floor with a small broom. "Art."
I never actually saw Street Legal in the old days, but back before the internet, it was hard to get foreign television. In my day, we only had 50 channels, and really thick screens back then.