It's been a while, so forgive me if this isn't up to scratch. A big part of this is the idea that Henry significantly legitimises Parliament by passing the various parts of the Reformation through Parliament, ranging from the Act of Supremacy (recognising Henry as Supreme Head of the CoE) to the Acts of Succession (that would annul Henry's marriage and was thus the main goal of him separating from Rome).

By performing such actions via Parliament (I'd argue these two are the most significant passed), rather than say Royal Proclamation, Henry is accepting that Parliament has the authority to do so. As Elton historically argued, this amounted to a revolution in Government shaping the modern British state. It was thus recognised that the King had most authority when acting through Parliament, and the King could not undo acts passed this way unilaterally.

So overall, Parliament switched from something that primarily resembled a court, and who the king must deal with to pass taxation (King and Parliament acting separately), to a more important legislating body that acted in tandem with the King (King-in-Parliament). The change is reflected in how much more Parliament is involved following the Reformation Parliaments; Henry VII saw Parliaments sit for 25 weeks, yet in a quarter of that time Edward VI would see it sit for 46 weeks. Likewise Henry's reign (particularly the portion after 1529) would see more legislation passed through Parliament than the previous 200 years.

tl;dr: Henry passes the Reformation via Statute not Proclamation, consequently the King acting through Parliament becomes the highest from of authority, and thus Parliament is called more frequently.