Given that circuit split, it's unlikely -- no matter how evil you imagine ISPs to be -- that they would start scooping up data and selling it immediately, and only in a narrow set of States. The FCC regulation was an attempt to restore an existing privacy situation, across the whole of the US market.
Again, it's extremely unlikely that with an impending privacy regulation being imposed, ISPs would proceed with monetising user browser histories for a short period of time before they were once again vulnerable to regulatory penalties for doing so.
If I may be less than oddly silent, I think we (EFF) didn't talk about this much because it seemed like various parts of the USG were (slowly) moving to fix a problem that came out of a court decision that could have gone either way.
You can read a little bit more about our work during the Obama administration (and before) on net neutrality here: https://www.eff.org/deeplinks/2014/07/deep-dive-defense-neut... . One of the points we talked about during that administration, and this one, is the risk of FCC over-regulation, and regulatory capture. If you want to view these challenges in a public choice theory (ie generally Republican) model -- at the FCC, the risk is largely one of ISP dominance, as it is traditionally the telcos that stand to benefit from investing in moving the FCC to their position. In this case, you actually have Congress stepping into to push them even more that way. That's a problem under a Democratic or Republican administration, which is why I think you saw more Republicans move to oppose the repeal than Democrats support it.
Referring to this privacy exposure as "something that may/will happen because of Trump" ignores that it is already Federal law and has been since 2015. Yes, in removing FTC authority over broadband, the Obama administration created this privacy exposure in the first place. That tap wouldn't shut off until next December at the earliest if the current administration did nothing.
That privacy ship has sailed. Broadband providers can have been sucking this data up for over two years by the time this particular Obama regulation would kick in, even if left as was. The Obama administration could have timed the FTC authority removal to not happen until replacement protections were in place, but, no.
The EFF is oddly silent about why they've been so oddly silent about this exposure for over a year now. Their partisanship is showing.