As Sqgs pointed out, it's a procedure.
If you carefully check the 1-94, it's one year after the entry date, and is irrelevant to your H1b expiration date.
CBP simply extends one year without necessarily knowing your other non-immigration status, such as H,L.
However, it won't affect your status after one year. You are good to use H1 for work and AP for re-entry next time--you will get another one year parole period.
Check PJ's blog, more answers will come up to clear your doubts.