I don't believe transient copies are the real issue here. Having a temporary copy stored locally in memory is more of a technical nuance than anything. That copy remains isolated and is not being distributed or shared. In contrast, using something like BitTorrent actively spreads copies across the internet.

There are also cases where loading copyrighted content is unavoidable in order to even view the license terms. For example, a website could deny the right to copy its content before you even see the licensing details. Temporary copies enabled through normal usage like this should be permissible.