Having her as a competing faction with Blofeld and so Blofeld tries to ‘kaboom’ her is logical. And Maddy turning out to be that character would doubtless be tempting to Eon to the final part of her reveal. But it’s surely too similar to Oberthingy revealing a ‘new name’. Plus the double-crossing lover has also already happened to Craig-Bond with Vesper.
For me it all jumps the shark (again) if her hostage status was faked. Bond came up with the idea to leap - if not they’d both have been kaboomed!