Depends on where you read it! If it was an ILCA site, it may in fact be true. I'm not aware of any such publication.
By-Law 1 states:
The use of flexible adhesive tape or similar is permitted to secure shackle pins and clips, and to bind sheets, lines and rigging, except that tapes shall not be used to construct new fittings or modify the function of the existing fittings.
As such, shrink tubing, similar to flexible adhesive tape in its use to align and bind the two traveler blocks, is LEGAL. The application has been one of the standard practices for a long time.
I personally think, he gives us readers at TLF a notice to the rights, that are guaranteed in the constitution of the Laserclass (I hope I´m right in that point...) for a racing/ nonracing Laserite, in relationship to our (here and there) ambiguious Laserclassrules we all have to follow.
I think, "God" has a well known name - at the Laserclass his pre-name is Jean-Luc (No no, not the person from StarTek...). Never have seen him... - luckiely...