SB, yes, catts can and DO continue to grow after every root has been removed. I have 2 catts in which I had to remove every single root. I have a large catt that smelled of rot and Jerry had advised that in those conditions, the best thing to do was remove every root, that he's done this and had faster growth and more blooms on rootless catts as a result of cutting than those he repotted without removal of all roots. My very first orchid was a catt that was in the same bad shape and Kevin assisted me in potting that one up with specific following instructions to get it begin growing again. Both plants have grown several ps.bulbs and continue to.
There is though a setback if you have to do this albeit temporary and as well can contribute to an overall wrinkle in the older bulbs but sometimes, unavoidable for the continued health of the plant.
No arguing, not even debating, just clarifying.....
Have a look at my 2 instances with my catts. You may find it useful.
Cattleya Crisis AGAIN! Hold The Laughter...please