soft launch

noun3

1. •
   The release of a product or service (particularly software) to a limited audience, often in order to gain data on the product's usage and acceptance by customers.
2. •
   (Internet, informal) The subtle or ambiguous announcement of a romantic relationship, often via social media.

   • Ms. Wright, who has done a soft launch on Instagram, shared that a healthy dose of mystery could be a good thing. — 2022
3. •
   The launch of a missile in such a way that the rocket motor ignites outside of the launch tube, ejecting the missile non-explosively.