For the first full trailer? Yeah, sounds right.
For the first teaser trailer? No way. You need to start building direct hype for this flick long before that.
And, if memory serves, every single previous MCU movie (all 20 of them: from IRON MAN in 2008 through ANT-MAN & THE WASP in 2018) already had an official teaser trailer out before the T-minus 6-months mark.
This is a first for the MCU. And I'm not sure it's a good move.
Unless the teaser trailer is spectacular. Then I redact all my concerns.