Was working last week.
Ah yes, I saw it now.
Advertising a €9.99 fare is now not exactly honest if you happen to be travelling with a child.
I have done dozens of Ryanair flights with family and never been assigned a seat apart at online checkin. Always got some combination of ABC-D or C-DEF without paying anything additional.
Now under the new system, if all of us want to sit close together, it's a minimum of an extra GBP 16 per return (2 adult seat reservation per direction). Over 25 returns a year, that's GBP 400 for Ryanair. If you happen to make a very late booking when all the standard seats are gone, even your children will be paying.