Indeed, on two points he was just simply wrong. First, he was wrong on infant baptism (but that’s forgivable) and second, he was wrong on the ‘perpetual virginity of Mary (which is forgivable but completely inexplicable).
That sermon was preached in mid 1522 and published on the 17th of the month of September. It’s still fine reading makes some really interesting points though, naturally, it doesn’t measure up to the standards of Zwingli’s theology to which we have become accustomed.
Go read it, you’ll like it.