Hell yes!
Most factories have 2-3 shifts. It would not surprise me if they ran the legit watches on day shifts; you know 7a-3p, 3p-11p. And then pump the fakes out on the late shift; 11p-7a!
At least that's what I would do. I have often wondered this very same thing myself, because how would rep makers be able to purchase eta movt's if they didn't at least have some reputable business?
This is certainly a factor in eta's move to phase out watch movt kit sales to third party builders.
I have a newer Invicta with that sellita sw200/ eta based movt. It's not bad, but you'd better wind it in full turns when you power it up. No rocking back and winding with half turns; you'll tear it up. At least I did. They replaced however.
Peace.