Home Forums Hardware Mac Desktops & Notebooks Purchase quandry: new hardware/32bit software

I had to be careful not to steal/get confused with deniro's thread title...

My late-2010 Mac Pro 5,1 is eight years old. It's a wonderful machine and is running perfectly. However, it won't last too much longer, I fear, and an iMac will replace it.

Here's my question:

When Apple announce the launch of Mojave and their latest updates of the iMacs, do you think any computer delivered after that will only launch in Mojave? Do you think Apple will still allow High Sierra to be installed?

I have Adobe 5 CS. Photoshop will work in Mojave, because it is 64-bit. But InDesign won't, and all of my documents are in InDesign. I tried opening one of them in LibreOffice and it was no go.

So, I'm wondering if it's worth buying an iMac now and just leave it in the box until my Mac Pro fails, rather than risk having to buy a machine that won't run my software.

Thoughts, please?