If flushing tissues causes issues with sewer systems and septic tanks, then that are not flushable and should be renamed. The public takes packaging at their word and the word 'flushable' insinuates that flushing the tissues is safe. If they are not safe for your plumbing, then it can be construed as false advertising.
It would be false advertising for a "flushable" tissues to be named as such if it can't be flushed. As soon as the word gets out that the product is not what it claims to be then their sales will plummet and they will ultimate be the cause of their own demise, for no good reason.
Yes, flushable tissues should be renamed fi they cannot be flushed. If they are not renamed, consumers will continue to believe they are able to be flushed. Flushing these tissues causes many ugly problems in sewer systems. For the good of our public works, these tissues should be named something else.
A product that is not properly defined only leads to problems. Too many things that should not be flushed are flushed anyway. Those items lead to costs and pollution that the public has to bear. Therefore, if a tissue is not flushable, for whatever reason, it should not be labeled as such.