No so.  Read some of the British papers.  There was a similar fire in 2009 in southeast London that killed 9.  The coroner's report and a special parliamentary commission strongly recommended sprinklers be installed.  The then Tory minister (2013) stated that 'we know sprinklers save lives, but reject them because it would discourage developers from building new housing.'  So your argument about grandfathering does not apply.