you can travel but if your H-1B is approved as a change of status, you will need to get a h-1b visa at a consulate abroad before you can return and activate your H-1B. The issue is really that most likely no consulate will give you a visa until about early September so if you leave in July you will have to stay outside the US until about early to mid September before you will be able to return once you get a visa, assuming that there are no issues or additional delays with visa issuance.
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