The ending is disappointing, yes, but it's fairly obviously the result of the series being axed, not something the author just randomly decided to do on his own. Depending on sales, it's extremely common for a publisher to simply inform a manga author that the next chapter will be the last. If...
This is skipping over a decent amount of context from the in-between chapters, which is probably a good reason why you shouldn't translate the final chapter without doing the ones before it first 🙄