I think everyone who read 'Solaris is the #1 Enterprise Operating System', raised an eyebrow, then read 'We have more than twice the application base of AIX and HP-UX combined' and chuckled.
No, Linux is not SysV based.
- Based on SysV standards - which GNU does for most commands, and which most Linux OSs did for initscripts.
- Based on Sys V code, which it obviously isn't.