I don’t think it has anything to do with last years data breach. They very clearly state that its about upgrading their website and systems. Most likely because they’ve been using a dated PHP based backend and disjointed schema. Now they’re owned by Collectors who uses modern web tech (Next.js based) that can be repurposed/rethemed for their other companies, such as Beckett.
I would take them at their word for it. Their website and backend was a total mess and even in the age of GPT-6 Astra and Fable 5, its not as simple as saying “update my website” to pull of a migration like this.