Disclaimer: I am not a lawyer and you should consult one if you have an emergency that requires traveling out.Nothing prevents you to go out of the USA, you donu2019t even need to u201creturnu201d your I-94 as it is now electronic. And traveling back into the USA with a B1-B2 could be possible, as long as you enter for a short business or tourist trip.However, if you are inside the USA on H1B status, and apply for H1B extension, it is not advisable to go out of the USA, as it would be consider abandoning your H1B extension application. So if an extension is in progress, and you go out, by default your extension is no longer approved.Consult a lawyer