I don't think so...Are there going to be minions? Powerful minions? A CR 17 dragon with powerful minions seems a bit too much for me.
It's mostly a question of aesthetics : i like the idea that some foes are powerful enough to be able fight alone.
For some of the "Figures/Alpha predators" of my campaign setting i will happily use minions [I'm considering a Winter Eladrin Warlord - CR 12 - with a pair of Winter wolves as hounds] but the Great Red Dragon is a solitary force of nature, an army all by itself.