He works at 2nd biggest US basket magazine - Tycoon walks in

The protagonist is a journalist and he doesn't like the nonsense "synergies" of the tycoon who buys the magazine.

During a conference meeting where the tycoon explains the new merging and synergies he asks a tough question and the tycoon answer with a big inspirational BS.

I seemed to remember the protagonist is a big A list celebrity like Gere or Clooney but I can't find it in their bios.

Any idea?

It might be Shattered Glass

Unluckily not..

What about In good company (2004) ?

Good suggestion. I had trouble finding this one thinking the lead was Costner. Grrr. lol but I'm betting you got this one. There's even a 'synergy' scene!

Getting closer, not yet .

The lead actor is around that age indeed, but the tycoon who buys up the magazine is more like third age.

He delivers his "synergy" sermon on an all-hands meeting, and when the lead actor asks the tough question the tycoon fumbles, clasps his hands to show the strength of "togetherness" and then tells him "and I'll leave you to answer that question".

Then we see a scene where the boss of the lead character berates him for putting the new powerful owner in such a tough spot.