I don't think the president would be told everything that is going on - and not necessarly only in Area 51 (even if it has been changed into a 'top secret' parking lot, which wouldn't surprise me).
" whats going on in area 51 , lads "
Kicking back a few with the home boys are we?
;-)
A better question would be where is area 52! Where they do the real stuff.
As the US gov know that everybody knows of area 51 they just send up a couple of rockets and dud weather balloon every now and again and it keeps people occupied.