Stick to a plan!
1. Was the ad targeting
you, or
your husband? The 60k United miles offer is a targeted offer; it may not be available your husband if he tries to apply.
1(a). ETA: The United Explorer card is subject to the 5/24 Rule. If you were targeted, you don't qualify and will be DENIED.
2. The offer on the United Explorer card bounces around from 40k to as high as 70k miles. A high offer like this will come around again, and if neither of you jump now, you will very likely be targeted again.
3. Your husband's CIP application is still pending. If you apply for the United Explorer card for your husband, and it's approved before the CIP, the CIP will be denied because of Chase's 0/30 rule. Because the United Explorer card is a personal card, your husband will very likely receive an approval decision immediately, then the
CIP will be DENIED.
4. Because the United Explorer card is a personal card,
it will take your husband to 5/24 and lock him out of all of Chase's UR-earning cards (particularly the business cards CIP, CIC, CIU, which wouldn't add to DH's */24 count)
until at least January 2020.
5. The CIP has a
80k UR signup bonus, the CIC has a
50k UR signup bonus, the CIU has a
50k UR signup bonus.
6. 1 UR point can be transferred to 1 United mile in 1000 increments.
7. You're considering trading an 80k UR signup bonus on the CIP, at the very least (and the
potential for 180k UR in signup bonuses across all of Chase's UR business cards, and their continuing earning power) for 60k United miles.
DON'T DO IT!