Will a engagement ring go through checked luggage?

AR enough asking if it allowed. Yes it is.
Are you asking will it get stolen from your luggage, prob lay not, but always a possibility.
I never put expensive jewelry on my checked bags, I always carry with me.
Never put anything in your checks bags you can not afford to loose.
Bags can get lost

Keep valuables in your carry on at all times. Keep the ring in its box.

If they select you to be searched, step aside with the TSA agent and ask them to be discreet about it if your future fiancé(e) is nearby.

A person can check any jewelry they want, but don't be surprised if it disappears.

if it's wrapped up in a box of course it will

No! Do not put jewelry in a checked bag. It will get stolen, or the bag lost