Because of course, that's the only sort of rape that is, you know, real rape
No it isn't but legally all rapes are not the same. The rape described in that post would be classed as category 1 culpability A in England, resulting in a sentence probably in the range 16-19 years, possibly higher in some circumstances. The offence we are discussing here appears to be category 3 culpability B, the lowest possible for sentencing purposes. Offenders in this category still normally get a prison sentence. This case is in the news because it is so unusual.
I'm in favour of '2'
I am not. We aren't going to stop teenagers having sex however desirable that outcome might be. The effect of this change would be to criminalise a lot of teenagers for behaving normally. And, given that the police didn't think the girl in this case was drinking under age and the taxi driver thought she was at least 20, I don't think it would have made any difference. She would have claimed she was 18 rather than 16 and would have been believed.