thats not true, he asked for the update shedule before season 3, and it was 3-6 months for most season 1+2 episodes. They become bigger each time... but the main reason for the long development time now are the animations. DPC didnt do that much complex animations in season 1+2, its a new thing he is doing since the interlude.10-12 month, no kidding.
You can call it his new "passion" he wasnt nearly that obsessed with high quality animations in the seasons before... and they take time... a lot. 335 animations for episode 10, he was able to render about 1 animation per day... you get the picture. If he would cut back on those he could release a episode like ep10 in about 6-7 months.
BUT he will not do so, he loves those pointless animations way too much... so yeah, now its a 10-12 months shedule, ep 11 will maybe come out just in time to make it into 2024.