64 bit Transition

What Rudegar said.

If you are concerned that some of the applications you depend on are 32-bit:

1) Hold down the option key, and from the Apple menu choose "System Information". On the left pane, under Software, click on "Applications". There is a column saying "64 bit"; click it so that the applications are sorted by this criterion.

Then see which ones say "yes" or "no".

2) If any application you depend on is still 32-bit, check to see if there is an update. If not, contact the developer to see if one is planned.

FWIW, 32 bit applications still work in Mojave, but probably will not work in the next macOS, 10.15.

the developer of the app needs to recompile it for the 64bit platform

FWIW, it's nothing to be concerned with until the replacement for Mojave is released. Probably towards the end of this year.