I would hope a 5.1 pdf would be released prior to the player handbook, with a list of 5.0 errata. Presently, we have 5.09 and an old errata months after the release.
QFT
Granted, this discussion is for brainstorming and musings, but yes, it's safe and a good idea to bring up the current status of T5: Marc has errata to do, and though he is thinking about several things at once -- and has non-Traveller jobs -- errata is his no. 1 Traveller priority.
Back to the subject. A Player's Guide shouldn't just be a third of the T5 Core Rules stapled into a book. It has to have reference material tuned to the player. I believe that includes a setting introduction. Some text might be abbreviated -- such as the skills text. It should not have referee material.
I also believe that setting material can be player-friendly, useful for solo exploration but also exploitable as a plot hook later. For example, the first activity after mustering out would be getting your bearings. It would be helpful to know where your character is when he mustered out; where she can go to browse equipment; where he can find a place to crash at night -- or alternately where her fief is located exactly and what it's got. What lowlife scum are available for underground connections. How to get to the Scout base or Naval base, and who you can talk to there.