The CP led consortium which won the 50 year concession for the Eastern HSR/3 Airports line in Dec 2018, started changing signage at ARL stations last August as they were officially meant to take over ARL operations in mid Oct 2021. You can see some pics new signage and upgrades from last October;
https://www.facebook.com/TrainBusAirplane/posts/422708266092760
https://www.facebook.com/DRT.OfficialFanpage/posts/1031421287634815
However, the handover was delayed for 3 months due to non payment of the initial deposit. Again, the new date for the payment in early 2022 was again delayed. Most recently, the consortium was meant to take over operations in late June, but I don't believe that has happened as yet. I suspect that the consortium wants to delay the intial payment and takeover for a long as possible while pax numbers recover and in the current economic context.
Pax on the ARL are up to 52.5k a day which is still less than the 72K+per day prior to Covid
Originally, when CP consortium (ITD & CRCC) won the bid for the Eastern HSR line they stated that they would commence construction in 2020. However, the contract was not signed until 2019 as the consortium had concerns regarding land handover issues from the SRT - read squatters and other land aquisition complications. Obviously, then Covid hit.
It was announced by the consortium 2 months ago that the ARL ext to DMK (1st stage of the Eastern HSR) would start construction by Sept, but I'm not seeing much happening on that front right now.