The Long Night And The Night Face

I have been classifying the four post-Imperial installments of Poul Anderson's Technic History as follows:

"A Tragedy of Errors," set during the Long Night between the Fall of the Terran Empire and the emergence of later interstellar civilizations;

The Night Face and "The Sharing of Flesh," set during the Allied Planets period;

"Starfog," set during the period of the Commonalty.

(I write "during the period of the Commonalty," not "the Commonalty period," because the Commonalty is an interstellar service organization in one of several civilized spiral arms of the galaxy. It is not itself a civilization.)

Hank Davis' Introduction to The Technic Civilization, Volume VII, Flandry's Legacy, partly bears out my above classifications:

"The remaining chapters of the Technic Civilization saga are set centuries, even millennia apart, with no recurring characters. Only one is set during the Long Night itself..."
-Hank Davis, THE WHEEL TURNS IN Poul Anderson, Flandry's Legacy (Riverdale, NY, 2012), pp. vii-xii AT p. x.

However, is this correct? In The Night Face, has the Long Night ended or the Allied Planets begun yet? In Poul Anderson's Introduction to The Night Face:

"Now the Empire has fallen, the Long Night descended upon that tiny fraction of the galaxy which man once explored and colonized. Like Romano-Britons after the last legion had withdrawn, people out in the former marches of civilization do not even know what is happening at its former heart. They have the physical capability of going there and finding out, but are too busy surviving. They are also, all unawares, generating whole new societies of their own."
-Poul Anderson, INTRODUCTION IN Flandry's Legacy, pp. 543-544 AT pp. 543-544.

Thus, the post-Imperial future history is as follows:

the Long Night endures through "A Tragedy of Errors" and The Night Face;
the Allied Planets begin to rebuild interstellar civilization in "The Sharing of Flesh";
civilizations have spread through several spiral arms in "Starfog."

See also:

Romano-Britons And A Fraction Of The Galaxy
The Introductions