Mortgages are fixed income instruments. There are 2 types of mortgages, fixed rate and adjustable rate. The article focuses on fixed rates, as adjustable rate mortgages are different for a variety of reasons.
Fixed income instruments are roughly priced like this:
Yield ~= risk free rate (corresponding duration treasury rate) + interest rate risk premium + default risk premium
1. Risk free rate (=corresponding treasury rate) is going up. Fed is pushing the entire yield curve up through Fed Funds and QT, not just the short end.
2. Interest rate risk premium is going up, because it is much more uncertain (compared to 2008-2018, or 2020-2022) where risk free rate will be in 1 years from now, much less about 5 years from now. We don't know what the Fed will end up doing. To understand this risk, you have to understand the duration of an instrument[1] and incorporate the uncertainty about the risk-free rate.
3. Default risk premium is uncertain, because the question depends on whether are we going to have a recession? Recession may depend on whether the Fed can engineer a soft landing.
So yes, 30yr mortgage rates will go up, because #1 is going up, #2 is going up, and #3 is maybe going up.
[1]https://www.blackrock.com/fp/documents/understanding_duratio...