So, I guess we can conclude from this that using the free version is not valid, otherwise the prompt would never have come up. The flaw in the new version seems to be its inability to distinguish between once having applied a trial key (everyone does this at the start), letting it expire, and then using the free license...and something else, which I assume from your earlier comment, is piracy.
Also, note that there is no letting the new trial key expire: it instantly expires in this context, as expected, since it should never have been applied in the first place.
Will the lengthy and misleading message along the top of the screen itself ever expire?