Absolutely true. As soon as you allow current to flow in the pickup loop, the pickup loop developes its own time variant magnetic field. This field in turn (and of geometric necessity) couples back through the superconductive loop generating a back EMF which acts like a resistance, damping the pulse.
Yes, very true! That's just one of the common problems with energy crackpot nuts - they don't understand or even know about things like back-EMF and energy conversion losses. Pretty much everything they say is based on just a little knowledge with no appreciation whatsoever with all the other principles involved. Put into plain words, they are grossly ignorant.
(Not to mention that most of them are also delusional and paranoid as well. What a wonderful combination of human attributes!!!!)