Don't forget, even when Ford didn't own Cosworth, they had the rights to use the Cosworth badge on vehicles, hence why there wasn't a Merc Cosworth or Vauxhall Astra 16v Cosworth (badged).

I'd also find it strange for the new owner of Cosworth not to do engine development work for other manufacturers (as now), as that'd be one expensive inhouse R&D dept.