Yeah it was. This is from when EVs were newer. Nowadays it doesnt matter as much.
Technically you might wear the battery faster charging it to 100%, but in the full perspective this doesnt matter at all. The car will likely not be in your possession when this wear starts to become noticeable. Even older teslas are holding up fine, having 95%+ battery capacity at over 10 years old only using supercharging (which supposedly is bad for the batteries as well).
Newer EVs have a healthy top and bottom buffer on their batterypacks while older EVs didnt have this, so when you charge your MGS5 to 100% in reality its maybe at 90% (depends on their buffers of course, but considering their battery warranty the buffer is healthy).
The only thing you absolutely should not do is leave the car for longer periods of time while the battery is either full (100%) or close to empty. The rest? Do whatever you feel like.