Let’s be clear. From what I can see, it’s the company and not the platform whose name is changing.
I believe that it’s because they don’t want their name and branding tied only to one of their platforms - especially as they gain more assets under their umbrella.
I hope this makes sense.
Of course it is the name that Zugerberg is changing if you have watched the interview yesterday. The purpose, technology and mission still remain the same but there is something to a name because it will now have a new logo and identity. You don't rebrand without changes either in the name, identify , technology and mission.