Bit of both; because of the lack of CDL, the ORR insisted on them drawing up a stewarding plan to keep the non-CDL doors safe. WCRC then failed two spot inspections, where their agreed plan was not being adhered to, so the ORR forced them to use CDL-only stock because they could not be trusted to adhere to the mitigations already agreed by the regulator.
You are conflating two separate regulatory processes.
The first is the operation of the Jacobite service where spot inspections (presumably after a tip-off) revealed non-compliance with the agreed stewarding plan for non-CDL fitted doors. This was subject to enforcement action, twice, including suspension of service.
The second is WCRC's wider non-CDL fitted door issue, which applies to their whole fleet, not just the Jacobite. The ORR signposted several years ago that there would be no further blanket exemptions from the CDL regulations, and agreed time-bound plans with other operators to fit CDL, but allow them to continue running. WCRC chose a diferent route and challenged it via a Judicial Review. Having had their case thoroughly rejected in the Judicial Review process, ORR have terminated the limited exemption that WCRC had that kept them running through the review. Having failed to engage and provide a CDL fitment plan, ORR will not be issuing any further CDL exemptions for WCRC unless or until WCRC change their approach.