Yes, it was intentional. You can't really publish the Rmd itself to Rpubs -- you can only publish rendered HTML. So when you click Publish on an Rmd file, the file was knitted to HTML as a side effect... unless the HTML version of the file was up to date, in which case that version was published. This lead to a lot of confusion; for instance:
- it's slow to render my Rmd; why is it rendering when I click Publish? how can I stop it from doing that?
- why does my Rmd sometimes have to be rendered before publish, and sometimes not?
- when I click Publish in the editor, why do I have to clarify whether I mean to publish the Rmd itself or the HTML output?
In RStudio 1.1 we tried to clear this up by making the Publish button more literal: now it publishes specifically what you clicked Publish on. That is, if you click Publish on an Rmd, you're publishing the Rmd code itself (to a service like RStudio Connect), and if you click Publish on a viewer or preview, you're publishing HTML output. Since you can't publish Rmd code to RPubs, there's no longer an RPubs option when you publish from the editor.
We definitely underestimated the number of people who used Publish on the editor toolbar to publish to RPubs; many people believed we'd taken RPubs out of the picture entirely. We're open to improving this in a future release of RStudio if we can find a way to do so that's less confusing than the prior configuration!