It all depends really, for me, Bach is open to a million of possibilities, but you will often encounter certain ideologies or groups that will instantly disqualify a different approach, either because that's how they were or weren't educated, or simply because they don't like it.
Phrasing is linked directly to articulation. I stand on the side that says and strongly believes that phrasing and articulation is completely open to each individual's point of view, idea and concept that one has of X piece. Also, for me, articulation also serves for contrasts as well. Bach's music has a very characteristic texture that it can become, at some point, repetitive and in need* of this contrasts, and the piano has the advantage of having a super clear difference between legato and staccato, non-legato, etc. I must admit, I do get extremely bored when I hear someone playing Bach ALL legato, or ALL staccato, etc. The possibilities and combinations are extremely numerous. Bach rarely wrote any phrasing and articulation marks because those were to be improvised by the performer. So, you can say that they are open to each individual's interpretation, but they do require analysis and a good reason for existing. The previous post is a good point of reference for you to start experimenting with the possibilities.
The same goes with tempo, I only remember the concertos having tempo indications, none of the inventions nor sinfonias have tempo indications. Same story with ornaments.
And if you find an edition that does have phrasing, articulations and tempo markings, those were most probably written down by the romantics.
In conclusion, everything is valid as long as it is coherent and has an idea, not just a random sequence of notes that make you say "Huh?".
* I do not mean that it sucks, but rather that it's incomplete without them. 