You may find that your floor joists have been hatcheted ( I can explain that if need be
) and will need to be repaired before you can go back with your new subfloor.
How will you regain the height?
The sub floors you have now are in fact the absolute best method of installing floor tile there is. It just isn't done that much these days. There are easier lighter weight methods but they aren't as good as what you already have.
If you joists are bowed now they will be bowed when the new subfloor is installed if you don't repair them.
Why can't you leave everything as is and tile over it?