No, it really isn't. If you cast a vote with the current rules stating your vote would count, and then the rules changed after you cast your vote, that is disenfranchisement. That is what we are looking at here -- the rules currently say any votes that were mailed by election day should count -- so anyone that sent a ballot on election day in Pennsylvania 'cast' a legal ballot. How is it now fair to voters who cast legal ballots to, after the fact, rule their ballots invalid?
Sure it is. If you go to vote and the power goes out -- sorry, you can't vote because the machines won't work without power; is it fair that you won't be allowed to cast a ballot? How is that different, since you were free to come earlier in the day, or to vote early.
Add to that, say there was a Democrat that controlled the power grid and there are allegations that he cut the power just to stop people in strong Republican areas, from casting a vote? It seems odd that there are allegations that Trump's appointed Postmaster General has been slowing the mail in swing states while, at the same time, it is Trump's campaign suing to prevent these late arriving ballots from counting -- if this were Democrats, you'd be claiming fraud.
Of course, it is worse because a
Federal Court had ordered the Post Office to sweep to find any ballots in Post Offices the day of the election, to ensure all ballots at the Post Office would be delivered before the deadline. The Post Office didn't do it, and tens of thousands of ballots, that were in Post Offices on time, were not delivered. Again, were this Democrats who did this, you'd be screaming about the voter fraud committed.