Remember that Wells Fargo is the 26th largest corporation in the world. They have plenty of money. They have lots of smart people (insert your "stupid banker" joke here) working for them. They have lots of highly-paid analysts that make these decisions. These are not spur-of-the-moment, panic-induced decisions. Wells Fargo also has a lot of experience with home values and mortgages, by being the largest Home Mortgage provider in the US (by dollar value), with $126B in home loans [1].
Long story short, they are experienced in home values and mortgages and they have a lot riding on them. They have smart people that have looked at the current and future state of home values and decided, that despite the potential revenue that could be generated from Home Equity Lines, there is too much risk in offering this product and they will stop offering it until further notice.
That's a big deal. Wells Fargo is leaving lots of money on the table by NOT offering these. But their analysts have decided that it is too risky. That to me, means that there is a lot of concern over future home value. We have been living in a housing bubble for a while. We all know it, Wells Fargo knew it, and this could be a signal that at least Wells Fargo is concerned that the bubble might be popping.
(I personally hate Wells Fargo, but did have a Home Mortgage through them until about 3 months ago when I sold my last home. I wouldn't borrow from them again however. This isn't a fanboy piece, but it is important to acknowledge their strengths when looking at signals like this).
[1] - https://www.housingwire.com/articles/41539-here-are-the-top-...