I work in EU too, but a lot of coders around here start at 10:00+.. especially in smaller companies.
The team there was shocked and maybe offended even, and I was informed it was verboten to work any of the next 3 days.
Differences in work cultures globally are staggering.
In my experience it really depends on the individual, team, and company just how strict people are with not working unscheduled overtime on national holidays to crunch a release or not.
But assuming that it will happen, that's a first for me.
Everywhere I've lived and worked (only two countries, tbf), the idea of working on a holiday weekend is just ... not considered, outside of being on call and getting paid extra for it or similar.