I'm not seeing it
"It’s an unusual result as Nominet’s last five years of data, lovingly presented here and depicted in our chart below, shows April is usually a pretty quiet month for registrations."
That data shows that in the last five years April has been the busiest month in two and the lowest in another two. March has exactly the same record. January is consistently in second but only first once, while Feb has been mostly third and never first. March and April seem a bit more erratic than Jan and Feb, but there doesn't seem to be any particularly meaningful trend visible, and certainly nothing to say that April is usually quiet. This year doesn't seem unusual at all, it's almost identical to 2018.