Yes, that's right.
As far as I remember, RCD's first hit the market around 1974, during the 14th Edition.
Rarely, you'll find an RCD-incomer protected board from that period (usually Wylex metalclad in my experience).
More often you find a stand-alone RCD in the tails.
Around the mid-80's, in the 15th Edition, you find the big builders like Barratt fitted 2 RCD sockets, one in the hall near the front door and one near the back door (often in the kitchen). Sometimes, if it was an extravagent build, there was one in the garage as well.
This was seen at the time to comply.
Later of course, the "16th Edition" board came in, which to most electricians minds, does not strictly comply, but was seen by the manufacturers as a cost-effective way to comply with the regs.
It's a similar story with the "17th Edition" boards now.
To my mind, there's only one route to full compliance regarding RCD protection: RCBO's to all circuits that have buried cables and/or socket outlets <20A.
Unless you have a TT supply, that is....but that's another thread....