That's correct. Repeater signs are only required and allowed where there the speed limit on a section of road is changed from the normal national limit by the Highway Authority under a Traffic Regulation Order. Hence whilst 20mph repeater signs were necessary to advise drivers that the national 30mph limit no longer applies on lit roads, now that the national limit is 20mph then no repeater signs are required or allowed. 20mph repeater signs will only be found on unlit roads where the 20mph limit has been set by a Traffic Regulation Order.

Hence local authorities in Wales will be removing some, but not all, 20mph repeater signs. Note that all 20mph limits will still have a large 20mph sign as you enter the limit and one indicating when it ends.