"pRease keep arms and Regs"
I dont think the Mexicana announcements are racism, and I dont think that all announcements should be queens English. However, substituting the "L"s for "R"s is stereotyping, and is actually pretty racist towards people from Asia. Its like saying all English people are posh and drink tea, or that all American people are fat and eat McDonalds all the time. Its really not true, and although most Asian people will have grown to accept it (I have seen a YouTube video called "How to do an Asian accent !!" where an Asian person (who had a very American-sounding accent might I add) spoke in a stereotypical accent), it may be very offensive to some. Most of the times I've come across people talking like that was to take the p*** out of people from the Orient.
I'm no over-the-top Tumblr "Everthing is discrimination" kind of person, but that in my eyes is very stereotypical/racist.
And yes, I understand racism. The kind of people who don't is those who shout "RACISM!!1!!!!!1!!" if someone states another's colour (while describing them).