Senior leaders are best placed to post on the category their company is building. They have seen the customer problems that shaped the product, the early hypotheses that did not work, and the market dynamics that opened the door to a new approach. That kind of context comes through best in a personal voice.
When marketing turns this knowledge into recurring posts, the result reads as positioning done in public. The leader contributes the take. Marketing runs the operational side around it.
The risk is staying at the level of vision. Category posts land when they are grounded in something specific. One concrete customer insight per post is a reliable constraint, and the managed track is where marketing keeps it in place.