They change stuff all the time just to sell the next version of bike.I don't know how they think 2.3 tyres are acceptable. They ride hard and less grip then 2.6. I'm guessing the next SL will magically feature 2.6 standard and claim holy grail status
They have done this on the 2020 Stumpjumper and Levo too. Both bikes have 2.3 rear, but they both feature a 2.6 front. I’ve ordered a DHF 2.5 and a DHR 2.3 to see how they go.
I dont get the logic of slim rear wheel. Ebikes power goes through that slim wheel so there is less traction. When I got rid of 2.3 on my enduro the bike was way better. More grip and better rolling and pedaling.
The pessimist in me says they do this to improve the range of the 500wh battery because that is what gets tested and not the grip of the tyres. Keeping the rolling mass down puts less strain on the motor and battery.