You'd think that after 20 years it'd be re-assigned. I think Spoony's rants (linked to above) were a bit extreme but I also, sort-of, agree with him that the people who made this movie didn't seem to care
too much about linking it to the original or even seemed to know anything about the real-world of computers and the internet. (Considering, as Spoony pointed out, that the CEO and the board freaked out pretty quickly on the OS being put on the internet and the negative effects of it all happened pretty damn quick. Considering even today whenever MS releases a new OS a pirated version makes it on line pretty damn fast and even times before the street date.)
It's
possible that the number wasn't "disconnected" just that it hadn't be used. Because it seems that the arcade still had utilities provided for it (most notably electricity and we could extend from that heat (gas) and water) it's possible was the phone was less "disconnected" and more "hasn't been used." That's to say the the number was still assigned to the arcade, and was being paid for, but just wasn't actually being used by anyone there (since the arcade was unoccupied and unused.)
Also, considering the conservation of mass and energy where did Olivia Wilde's physical body come from to appear in the real world? Did the LASER draw the billions of terrawatts it'd need from the powergrid in order to create the energy it'd need to make her mass? I mean at least Sam's body mass
went somewhere and existed. Yeah it'd still take a shot-ton of energy to decompile and reconstruct it but at least it has something to go off of. But Olivia Wilde's character was made out of
nothing! Wouldn't want his electric bill at the end of the month.
Oh, and just to mention again, holy
HELL she's hot in this. She was cute and fun too, loved the way she was laughing about the goings-on in the car when she first got Sam and other moments with her. Hell, this movie is worth watching for her alone.