That is not correct. Apple has told developers that macOS 10.13 (High Sierra) being released later this year runs 32bit apps with no issues whatsoever (and I can confirm this), and that macOS 10.14 (possibly in 2018/9) will also fully support 32bit apps but there might be a message displayed to the user that the app needs updating to 64bit in the future, much like they have done for iOS 9, then iOS10 with messages, and then iOS 11 which no longer supports 32bit. So I would expect that 32bit apps will no longer run in macOS 10.15, possibly arriving in 2020. So there is no need to worry just yet...
As far as Yummy FTP apps are concerned, I have an announcement to make in the near term which covers 32bit vs 64bit and other topics.
Stay tuned
