If the Supreme Court does decide to overturn Roe and leave abortion up to the states, would passing the Women's Health Protection Act allow Congress to pre-empt any state laws prohibiting abortion, or does the Tenth Amendment prevent this?
A ruling that overturns Roe would list specific reasons, so we'd have to see what the articulated principles are. The commerce clause is the obvious least-questionable weapon in the federal arsenal.
The key weakness in Roe which is under attack is the viability standard. Roe's description of viability is that
Viability is usually placed at about seven months (28 weeks) but may occur earlier, even at 24 weeks
but that was judged according to technology of 50 years ago. If "viability" itself is swept away, the prospects are dimmer for any federal intervention. But if the court allows a state to determine that viability exists at 15 weeks, then we have a potentially chaotic situation where any state can pick a number (let's say that they hard-code 15 weeks as the lowest legal number but also setting 28 weeks as a legal upper limit).
This being an issue with clear interstate commerce implications, the Constitution gives Congress the sole power to regulate such commerce. Hence marijuana is technically illegal throughout the US (and was actually illegal until that changed), by dint of a federal law enabled by the commerce clause.