I think some are being harsh on Omega and also confusing the general history of Swatch.
My history is rusty but ETA's job, such as it was as part of ASUAG, was to provide the Swiss watch industry with Ebauches. Omega/Tissot as part of SSIH were completely distinct.
When they both blew up thanks to the quartz crisis, Hayek butchered/saved/frankensteined the corpse of ASUAG into SSIH creating what became Swatch group, hence Longines and Omega both using the same movement's when they'd previously both been distinct. Fast forward thirty yeats and Hayeks plan before he died was for stronger distinct brand identities within Swatch group, and his ending supply of ETA ebauches was part of his plan of forcing non-Swatch manufacturers into doing the same.
But ETA was always intended to be an ebauche manufacturer for the benefit of the whole (Swiss) industry, which is why it was such a huge issue and why Swatch group limiting ebauche parts is a different issue to Omega limiting parts. One is Omega's business, the other affects the whole industry it was created to support.
The wiki's on SSIH & ASUAG are basic but give an idea as to how huge a mess the whole collapse was:
http://www.watch-wiki.net/index.php?title=ASUAG
There's a good unauthorised biography on Nicolas Hayek which deals with the origins of Swatch group that's also a good read should anyone be interested.