I-94 basically means the validity of your staying in the US as a non-immigrant.
I-94 on passport is for travel purpose. The one that really matters is your validity of non-immigrant stay.
For example, if you get h1 renewed, you automatically get a new I-94 card with the approval notice. It doesn't matter whether you replace the old one which is on your passport (I-94 numbere is the same if you have not traveled abroad again).