Although this rumour is certainly a possibility, Fathead might be a bit cautious before launching into another spin-off where the central lead character might kick the bucket partway through filming a series.
Okay, I'm sure Aldreds got quite a bit of a fair innings left in her yet, but she's 60 and only about 10 years away from repeatedly peeing herself and her false teeth rattling and falling out all the time, and we all know just how ageist and youth orientated Fathead and the BBC are.
I mean, could you imagine her huffing and puffing, legging it across some BBC car park chasing after a rogue Slitheen, only for her bowels to suddenly vacate and start rolling out of her trouser leg, and where she then has to improvise dialogue with, "Oopsy Poopsy! Now what WOULD the Professor do in a situation like this?"
They'd have to give her a sonic colostomy bag or something.
Fathead might decide to do a bioptic "early days" series of a Classic companion instead, where he can re-cast the part to some bratty snotty nosed drama student, such as "The Sarah Jane School Days" or "Lethbridge Stuart: The Cadet Years" etc, so that he only has to worry about his lead actor falling into drug addiction and suicide instead of incontinence and slipping the mortal coil.
Yup, I KNOW it sounds shite, but that makes it FAR more likely in NuPooh/Fathead circle jerks and those Yanks at Disney are singularly obsessed with repeatedly raking over the bloody origins and rewriting mythologies of franchises ALL the bloody time.
As soon as they get their grubby, greasy, puffy hamburger hands on ANY property, it's the first thing they want to immediately balls-up. They just can't leave it be for longer than 5 ruddy seconds. It's something hard wired into the Yankee-doodle psyche.