...did Canon or Nikon introduce overnight the 60+ lenses in the EF or Nikon mount...
Here are the first few years of EOS:
YEAR M Lens
1987 3 EF50mm f/1.8
1987 3 EF35-70mm f/3.5-4.5
1987 3 EF35-105mm f/3.5-4.5
1987 3 EF100-300mm f/5.6
1987 4 EF15mm f/2.8 Fisheye
1987 4 EF28mm f/2.8
1987 5 EF70-210mm f/4
1987 6 EF100-300mm f/5.6L
1987 10 EF135mm f/2.8 Soft Focus
1987 11 EF300mm f/2.8L USM
1987 11 EF28-70mm f/3.5-4.5
1987 12 EF50mm f/2.5 Compact Macro
1987 12 EF50-200mm f/3.5-4.5
1988 6 EF28-70mm f/3.5-4.5 II
1988 6 EF35-135mm f/3.5-4.5
1988 6 EF50-200mm f/3.5-4.5L
1988 10 EF35-70mm f/3.5-4.5A
1988 11 EF24mm f/2.8
1988 11 EF200mm f/1.8L USM
1988 11 EF600mm f/4L USM
1988 12 EF100-200mm f/4.5A
1989 4 EF28-80mm f/2.8-4L USM
1989 9 EF50mm f/1.0L USM
1989 9 EF85mm f/1.2L USM
1989 9 EF80-200mm f/2.8L
1989 10 EF20-35mm f/2.8L
More here:
http://www.northlight-images.co.uk/Canon_new_lenses.htmlFor Canon the EOS mount was difficult for pre EOS users as they could not so easily use old glass on the new Canon standard without many issues.
Nikon fudged their way into AF so the recent fully electronic mount has had a mix and match history, which has it's pro's and con's but still uses the same basic mount
Not disagreeing with your comments just a reminder of what happened...