That is because you call it H1B transfer, but in reality it is a new application for a new job position, just that you can do it any time and not wait for the lottery. RFEs are part of the process, if your supporting documents don't establish that you have the qualifications for the new role, you need to provide supporting evidence. It has always existed, regardless of any administration.
Also, because it is a new application, your old one does not expire, so you can always continue your current job till you sort things out. And you can always file a third application with a third employer if things don't work out with your RFE. Changing jobs isn't as crazy as people make it out to be, unless you really don't meet the minimum.
PS: Been doing it for more than a decade without any problems