It's prime Redmi time, so it's no surprise that rumors and leaks of the upcoming mid-rangers are starting to crawl out of the woodwork. Actual specifications and prices of the Redmi Note 5 may be inconclusive at the moment but sources have billed the Xiaomi favorite to be launched before the popular 11/11 shopping festival in China.
https://www.notebookcheck.net/We-may-be-getting-the-Redmi-Note-5-within-the-next-few-weeks.258712.0.html
If it's really is 617 rather than 630, then my guess is correct. Xiaomi is indeed cutting corner due to offline/physical market expansion. They are gathering money to pay that $1B loan.
Some notable changes
Redmi Note, from 650 in Note 3 to 625 in Note 4 and then to 617.
Mi Note, from 8xx series to 660.
Also, new Mi6 with 4GB RAM which most probably will be sold not only in China but India and SEA region as well (maybe even the region where Mi A1 is being sold)