dnd 5e – What is the current situation of Cyric in the Forgotten Realms?

I am DMing a homebrew campaign in the Forgotten Realms, the subplot involving the cleric is heavily linked to the past history and current situation of some of the gods. I am now interested in the fate of Cyric.

In the year of the Blue Fire (1385 DR) Cyric, with the aid of Shar, murdered Mystra, causing the Spellplague. We can read in Grand History of the Realms (page 159) that

Tyr, Lathander, and Sune move against Cyric and successfully imprison
the Black Sun in his Supreme Throne, under a sentence of house arrest
to last one thousand years.

This is confirmed in the Forgotten Realms Campaign Guide (page 74) for DnD 4th edition:

Tyr, Lathander, and Sune united to imprison him in his nightmarish
playhouse of a plane, the Supreme Throne, where he remains to this
, alone and increasingly insane.

I read to this day as the Year of the Ageless One, i.e. 1479 DR, as written in the same guide at the very beginning of the introduction via Elminster’s words. The Sword Coast Adventure’s Guide sets the current year to 1489, then only 104 years has passed since Cyric was imprisoned. At page 27 there is only a little paragraph about Cyric and its church, without any details about the imprisonment.

I wonder what are the consequences of its imprisonment on its church and worshippers, since it seems there are not anyone. Is Cyric actually free and he can roam wherever he wants? Or is he still confined in the Supreme Throne?

I know that it is a homebrew campaign and (theoretically) I can do whatever I want, but I prefer to be as faithful as possible to the official campaign setting.

If you have any details coming from current adventures (Princes of Apocalypse, Rise of Tiamat, etc), please use the spoiler quote.