I don't know what 'taken from arcades' means.
Namco doesn't go around telling arcades to remove their cabs, right?
But if you mean, "how long will they actively support" i'd guess they'll have new DLC stuff for about a year and they'll sponsor tourneys for 3 years or so.
But totally just guessing.
Guys, you don't get what he's trying to say.
They want to actively support the Arcade version long after release, but the Arcade version's popularity will definitely die down once the console/Steam version releases, so how long is "long after release"?
Of course they won't go around telling people to remove the cabs. They don't have to, because arcade operators will do so themselves once they notice that people don't come to play anymore. At what point will Namco say "Screw it!" and stop supporting them?
How long is the Arcade version going to be profitable enough for Namco to keep supporting it?