The developers of Genshin Impact announced that the presentation of the next update will take place in early November. More precisely, on the 3rd, the event was originally planned to take place on October 27th.
HoYoverse did not talk about the reasons for the postponement, but, most likely, the authors just need time to prepare. Usually, if studios encounter technical difficulties, it takes much longer to resolve them. The release of the patch, judging by rumors on the network, will take place on November 8.
There is no word yet on the contents of Genshin Impact update 4.2.