Not to deflect by a Tu Quo Que response, but isn't that exactly what the Democrats did in 2016? I seem to recall all sorts of claims the election was tainted; by fraud, by foreign interference, or both.
Immediately followed by demands for recounts, attempts to encourage unfaithful Electors, petitions from all sorts of professionals (mental health, medical, legal), educators, business leaders, current and former government officials to keep him out of office. Then there were also Congressional challenges to the validity of electors in 2017 but no Senator supported them. Followed by demands Trump's own Cabinet use the 25th Amendment to remove him as unfit.
Now anything is possible, but your assertion that despite these new voting laws Republicans will "scream fraud" and deny the results simply because they lose an election is simply another projection. IMO that would only occur if there is a successful attempt by Democrats (as they are trying to now with HR 1 "Voting Rights" law) to Federalize voting.