:::I can see that having a dedicated section summaring the reasons for the break-up would have some benefits, but overall I disagree with its addition for several reasons: 
 :::*Sections 1 to 4 of this article are in purely chronological order (it's only with section 5, "Musical style and development", that we bring together stuff from all over their career), and that pattern is broken if you add a break-up section within section 3. 
 :::*Adding such a section would only duplicate material that's already mentioned in the main chronology. 
 :::*Although I can't find a page where it's specified, AFAIK single-paragraph sections are discouraged at Wikipedia. In order to be worth adding, the section would need to be expanded by a couple more paragraphs. 
 :::*At the moment, the reasons for the break-up are mentioned as they come up in the main chronology, and the full article The Beatles' break-up is linked to both in the lead section ("After their break-up in 1970...") and in the History of The Beatles template at the start of the 1957–1962 section. I think that prominent links to that dedicated article are preferable to a new section that breaks the chronology and duplicates content from elsewhere. (In my opinion, the only big advantage of having this new section is that it gives us an excuse to use a Main article: or Further information: template to link to The Beatles' break-up.) 
 :::I've noticed an inconsistency that's come up with the addition of this section: the section "Abbey Road and Let It Be" mentions 10 April as the date of McCartney's announcement (citing Lewisohn and Spitz), and the article McCartney (album) gives the same date; whereas this new section and The Beatles' break-up specify 9 April, citing an online fansite version of the "self-interview". Maybe the difference in dates is because one is the date the Q&A;/press release was carried out and typed, and the other is the date the pre-release copies of the album were sent out to critics? 
 :::