No issues whatsoever with respect to H-1B sponsorship but potential issues with respect to green card applications, particularly PERM-based applications because of the ability pay requirement and because of issues related to ownership/equity held by the employee.
A company sponsoring an employee for a green card must show that it has the ability to pay the offered wage and this is more complicated when the company just has funding and no revenues or limited revenues. Also if the sponsored employee owns more than 5% of the company, USCIS could question whether recruitment process was done in good faith.
What are those issues?