For one, you are assuming that they are telling their staff not to post their own pictures to their official company social media outlets to promote zeiss optics when it could be simply be to tell them not to use some stock photo to advertise their products. I went to the zeiss hunting facebook page and they advertise their optics. I don't see anywhere that staff are posting their personal experiences so I don't think that is what they are referring to. As for their long range optics, they don't advertise it as tactical. They advertise it for long range competition as well as long range hunting.
I think the memo is probably true but could have easily been sent out 10 years ago.
The "Pro staff" referenced in the post would constitute people that are sponsored by or receive products from Zeiss for marketing purposes. Basically Zeiss pays them in either money, equipment or both for them to promote their product on their own social media pages.
The post directly mentions that it was sent to Pro staff members this week by Zeiss and that they followed up with someone who works at the company to confirm it's authenticity. That memo implies that Zeiss does not want to be associated with anything in their "Don't" category and does not want any of it in their marketing.