It's important to keep in mind that most non-EV uses for lithium batteries call for charging on a daily or near-daily basis. In that case, charge cycle count is pretty important and it's the metric that most all these studies are aimed at maximizing. If charging to 100% gives you a useful life of 1000 charging cycles but charging to 80% yields 3000 charging cycles, you're talking a useful battery life of only 3 years versus 9 years in a daily charging scenario.
EV's are different. A Bolt will give you ~250 miles on a full charge, which equates to only 400 charge cycles for 100,000 miles. By extension, it only takes 1000 charge cycles to get 250,000 miles. In other words, you might in theory sacrifice a lot of charge cycles by charging your EV to 100% every time but in practice, cycle life is likely not going to limit the life of the vehicle.
This is why I say "don't overthink it". If you want to charge to 100% every time, go for it. You may sacrifice a bit more pack range late in the life of the vehicle but your GOM will likely be more accurate and if it gives you peace of mind to have a "fuller tank" or if you sometimes need to take a longer unexpected trip or you just want to plug in less often, it's a rational tradeoff.
If you want to baby your battery to get the longest cycle life or fear that the Bolt's batteries aren't as robust as they should be and want to limit the chance of them failing catastrophically, or you don't really know what the truth is but figure it can't hurt to follow conservative guidance, that's fine too.
I shoot for the middle ground because my use case is short trips around the city with an ICE vehicle for planned or unplanned longer trips. I charge to 90% routinely and to 100% every fourth or fifth charge to let the BMS top-balance the pack (which helps range) and recalibrate the GOM. If that drops my car's theoretical life from 600,000 miles to just 500,000 miles, I can live with that.