The ceramic tile floor in our kitchen was installed only 4 years ago by the previous owners but they just laid plywood over several old layers of flooring instead of removing all the old flooring and installed the ceramic tile over top all the layers. The result is that the kitchen floor is a good inch or so higher than all the other flooring in the house. The installer had to cut down 7 doors to clear the kitchen floor height and install oak saddles between rooms. Also all the baseboard/floor moulding is noticeably shorter due to the height of the flooring. My questions are:
(1)Does it matter that the ceramic tile was installed this way, over the old layers of flooring - other than that the kitchen floor is not at the same level as the other floors? Though when we had a new dishwasher installed the installer almost couldn't get it in place due to the height of all the flooring!

(2) We will be remodeling our kitchen in a few months, should we take this opportunity to rip out all the kitchen flooring down to the original level (even though the ceramic tle is fairly new) and lay new flooring at the proper level or is it not worth the trouble and expense? Any guidance is appreciated!

If your floor does not have any cracked tile or loose grout, consider yourself lucky if the old flooring under the ply is multiple layers of vinyl or an old hardwood floor. The plywood probably saved it from going bad. If you are replacing the cabinets the new ones may have a different footprint than the existing ones, meaning there may be a hole where there isn't right now so I would plan on ripping it all out and doing it right. We can help you on what kind of prep needs to be done to ensure a new tile floor does not experience any cracks down the road.

In answer to your question, yes! Your tile floor is only as good as whatever the previous owner covered up. Get rid of it while everything else is being torn out instad of trying to tear out around beautiful new cabinets. You'll be glad you did.