The maximum learned battery capacity is a reference to the actual battery capacity of the battery inside your mobile device. It's a constant.
The estimated battery capacity is a variable, It depends on a correlation between the battery capacity, with the rate of discharging and time to recharge.
So if the estimated battery capacity of your battery is 95%, that's an indicator the battery is still in pretty overall health. A 5% loss isn't significant. All smartphone batteries age so it's inevitable that it will gradually decrease over time. You'll see your battery drains a little faster and takes a longer to recharge, hopefully it'll be several years before it becomes a problem.
Regarding if you charge your phone up to about 90%, that doesn't invalidate the estimation. It is a better practice to increase the battery's longevity, as opposed to charging it up to 100% all the time. So keep doing it (the common wisdom states 80% to be recommended max but whatever). So it doesn't invalidate the estimation, it does however indirectly affect it cumulatively over time. (Every battery has a set number of charge cycles -- if hypothetically your battery gets tapped for 33% every day, after three days or so that adds up one charge cycle.)
