I think there is some truth there, rap is the doo-wop of the "internet generation" (kids born 1985-1990) doo-dop was created, it got big, it dies out and in the 80's it came back but it just wasn't the same. then doo-wop died out until this day.
the same thing is with rap. in the 70's and 80's it started and got big and in the 90's it was still big but it sort of "died" out when we had the boy band fad, and rap came back but it isn't the same. now rap has to die out or something like that.
altought I think some records that changed the game were
JJFP- he's the DJ
1st rap grammy
wu tang-enter the wu-tang 36 chambers
wu tang has a damn mythology behind it (kung-fu movies,records,the wu-tang manual)
beastie boys-license to ill
1st white guys to really make it big
Michael Jackson-smooth criminal
michael actually has some kinda rap lyrics which alot of pop artists have used that style since.
kid 'n play-2 hype
they started to sample different types of music as opposed to others from that time.