Starting buff in the Jungle has always been the Meta

It has been Krugs or Gromp for the majority of the last two seasons.

The only real reasons to start buffs in the last two years were:

• Avoiding the enemy jungler cheesing you at your buff
• Level 2 ganking with Red Buff
• You could otherwise run out of mana before clearing the second camp (i.e. Hecarim)

...what all season 6 it was starting gromp on red side, and krugs on blue

That's not true at all. A huge majority of junglers started krugs or golems. Hell I even know some low bronze people that didn't even touch buffs until 7 minutes into the game

I've only leashed buffs to Evelynn, and thats cause my friend who plays Eve always invades their Red/Blue, so the buff helps