Sure! As linked in the OP of both this thread and the signups thread, this tournament is subject to the
general tournament rules and guidelines, which says right at the beginning (first paragraph if you exclude the "what is this?" preamble and links to other resources) that there's an expectation that players log in periodically. Making sure players are aware of when they've been given a substitute opponent is a part of why this is in the rules.
When your new opponent was
subbed in, the host tagged you so that you would be alerted to look at that post the next time you logged in. Reasonable efforts were made to let you know that you had been given an opponent, so this is not a fault on the host's part.
It would also be unreasonable to your Round 1 opponent to expect them to schedule and complete a game with you within the next 26 hours - the length of time before the extended games deadline.