Intuit announced last year that they would no longer develop or update QuickBooks for Mac beyond the then current version for 2016. It was not a surprise at the time, as it had never been fully supported nor had it had much in the way of improvements in recent years.
However, there are strong indications and sources reporting that Intuit has decided to release an updated version for 2019. There has not been an official announcement yet, but sources confirm it is coming. Stay tuned for further developments.