The title may be misleading, but IMO not for the reasons you mentioned. "90%" is based on generation right now, live. On the site from the post you can see that for the last day (24h) renewable generation was 66%, for the last week 46%, for the last year 42%. So it's nowhere near 90% renewable in general, but it is 90% at the moment (there's sunlight and good wind). Emissions on the website from the post are lower than on the website you linked - 107 g/kWh for the week, 124 for the year - but I don't know why that is.

Because nuclear. Which is a great 20th century French achievement !

If the EPR2 doesn’t spiral into costing £17.5bn per unit as the UK-PWR has, perhaps we can get them in to “rustle me up a nuclear power station” or two, in the words of Tony Blair.

France has an amazingly developed grid, with a lot of nuclear. But I think there's a risk of seeing grid make ups as "one size fits all". Norway and Sweden do well with huge amounts of hydro storage, but few countries have the geography for that level of hydro. Similarly, the UK has an abundance of offshore wind (especially in Scotland), so further developing that (rather than focusing heavily on nuclear because it works in France) is by no means a bad idea.

France has much more nuclear. You can argue that is better but even if you agree it would take decades to get there.

That's only because that chart isn't bookkeeping nuclear as renewable, which is misleading at best.