The two revs help charge up the tensioner with oil
I don't know that you have to do it but it does help remove any slack in the chain and reduces stress on the guides.
If you don't want to bother with removing the fan again, crank the engine with the starter only - pull the feed from the ignition coil to the distributor before turning the starter key.
The tough thing about removing the fan is getting the four bolts accessible - you can make it much easier by simply using the power steering pump bolts (22mm) to turn the fan, bringing each bolt uppermost in turn.
I would remove the fan. 1 hour, no heartache.
Note my approach to installing the new tensioner - it's very tough to do using strength alone.