Not in the slightest, Fed didn't cruise to that AO final, his level was very up and down in every match he played in AO save the Berdych drubbing and that just continued into the final. If anything he did well to raise his game in the F after that very lackluster showing against Stan in the SF, Nadal looked much better against Dimitrov for comparison.
2017 AO wasn't the case of Fed zoning and Nadal being in poor form and it still went 5 sets regardless of how much Nadal fans are trying to portray that scenario. Both were struggling on their road to the final, inconsistent but showing moments of brilliance. What tipped the scales in Fed's favour were improved topspin BH, better tactical approach and not playing 5 matches on clay in a row or something leading up to the sole meeting on HC/grass this time. Other than that, this his huge gap in form that you're suggesting didn't exist in AO.
Fed played much cleaner tennis in IW compared to AO overall, the rustyness wore off and he had no huge dips in form that were characteristic for his AO campaign. However IW has suitable conditions for Fed to handle Nadal (ball flies through the air fast, tough to defend as Fed himself said), people conveniently seem to forget/omit to mention their 2012 IW encounter where 30 year old Fed straight-setted Nadal who was in some of his career best HC form.
We don't know if IW will be reflective of 2017 Fedal, we're now entering the part of the season where conditions are decidedly in Nadal's favour against Fed (Miami and clay) aside from Madrid. Not to mention that the wheels could still fall off for Fed in any given moment (he will turn 36 this year afterall) and Nadal has been written off frequently in the past only to stage a successful comeback so we'll see, it's early days still.