I don't think so. It's not uncommon to run Oracle on Solaris + SUN hardware. Not a large market but one with high profit margins. Why would Oracle want to kill a cash cow?
For years, Solaris was the "original" platform upon which Oracle was developed. Everything else was a port. Solaris got the patches first, etc.
Several Oracls DBAs I know used to say "if you want to run Oracle you might as well run it on Solaris"
That is true, but Oracle recently has been pushing Linux, not Solaris. The Exadata, which is Oracle's first attempt to to build a database appliance on Sun hardware uses Linux, not Solaris, for example.