Immigration and start ups

Spouse is thinking of joining a start up firm that was initiated only 1 month back. Spouse is on an H1b and will apply for a transfer before joining the company. It is started by an ex employee of the startup spouse was earlier working with, which was later acquired by a bigger company. The new company has a total strength of 2 people right now (both are employees of the previous start up company that got acquired, they are both Americans and have no immigration issues, but are willing to support spouse's immigration requirements). Given the current immigration situation and tough H1b scrutiny, is joining a start up a good idea?