I wouldn't call these Transformers "bootlegs" because...bootlegs are of terrible quality and will break easily (remembers my first bootleg, the Power Rangers Megazord with Dragonzord armor...missing a vital part, though). These are of actual good quality AND their articulation is amazing. These look like they can do amazing and realistic poses compared to some of the other transformers.
I've fallen into this trap myself. Not ALL bootlegs are of terrible quality. All you need to be a "bootleg" is to be a non-official product attempting to pass yourself off as official. Quality doesn't come into it, in fact the better quality the bootleg, the more likely it is to sell well.
Another thing to keep in mind is the difference between a simple knock-off and a bootleg. A knockoff would be the red, green, blue, and yellow totally-not-devastator that I bought at Walgreens. But he was sold in a pack with crappy cardboard packaging and with different names for all the bots.
As you can see, that's clearly identical to the real Devastator, but he's not trying to be passed off AS Devastator. Like RC Cola is to Coke.
What a lot of these TF products being discussed are, in actually, is closer to a knock-off than a bootleg. But they're not knockoffs because they aren't trying to be a cheaper alternative to the original. What these would be is...kind of tricky to pin down. They're borderline trademark infringement (not copyright, trademark)...but I suppose the best word is 'homage'.
You can think of them as imitations of the originals if you want. But don't think means anything about their quality. And that goes for all knock-offs, bootlegs, OR unofficial homages.