The last I was reading them, Psylocke was still British.
Psylocke is still British, she's just also "physically" Asian.
In the real world, there are more than one or two British citizens who... Oh? You just didn't understand what you were saying when you said it?
In the mid 90s a seemingly Japanese assassin showed up who was driving Betsie's original body but with her hard core born and raised pure-bred anime themed super ninja mental state, despite for all intents and purposes being a roundeyes member of the British Aristpocracy.
(How many places in the queue did Brian Jump for succession to the throne when he went public as a Super Hero?)
I think there was some bleed over between the two during the process, when they traded places in the changeover, since when the dust settled, they were both purple haired telepaths.