I'd say that's normal, and not at all uncommon on other cars generally. It's slightly irritating I suppose (leaves streaks etc.) but the washer fluid has to go somewhere and, as you say, easy to live with.
What I do like is the XF's very efficient use of relatively small amounts of washer fluid - having the jets on the wiper arms is such an obvious idea I don't know why it's not a feature of all cars. And the XF squirts a measured 'dose' from a single press of the washer button, no need to hold it pressed, and a further squirt on the next sweep of the wipers - clever.
You'll also find that there's a small arc at the base of the wiper sweep that doesn't get washed, which is also slightly irritating, but I've found that this only happens on the move - use the washer while stationary and, with the help of gravity and no slipstream, the whole wiper sweep gets clean.
The extra, single wipe, to clear a few more dribbles is a nice touch (seem to recall that's long been a feature of Saabs).
And one more, final, 'on the other hand'
, I do wish you could somehow switch off the automatic headlight wash when the lights are on (just as easy to live with though).
