July or August seem to me to be way too early for finishing the game based on the current update flow. Just the progression with the story until next in game Sunday will take 2 or 3 updates. This meaning we will have all the story, events and POVs at the earliest in March update and more realistically in the April update. And from April until July there are only 3 months or counting 4 for if August is to be considered.
There are quite a lot of plot/story lines and loose ends that need to be tied up and completed. Them being:
- Council story that is nowhere in terms of relevance. We know that they exist, can do stuff and have some secret plan and not much else.
- Just some characters had any significant IRL events up to this point. Them, being Liz, Alice and Kyoko. The rest of the side characters and main one did not have yet significant IRL events
- Alice and Klein stories have no clear relevance yet to justify their presence as characters. Their roles could have easily been substituted by an FOG quest and some random NPC events IRL
- Kyoko story that has been basically put on hold and only referenced as a nice to have subject for the blog. And as Alice she still needs to become relevant in any way
- Sinon story that seems to be all over the place, with no clear destination yet for her story line
- Sugu that is used only for incest fan service and a convenient plot device when needed
- Liz just become relevant and is getting some purpose in the story, but her story still needs more to be fleshed out
- Asuna and Inoda that have almost exhausted FOG relevance and slowly moving to IRL
- Kirito that still has plenty of quests to complete and decisions to make before any work on the endings can start
The only way that Fujino can complete the game by the end of the summer is if he starts working full-time on the game or just rushes everything to be done ASAP and move one with something else. A more realistic time frame for the game completion would be November/December if everything is going well and no major issues are met by Fujino. And is more than certain that there will be other 2 months update cycles going forward.
In regards with the endings, I would say they will need more than one month of work to be completed. As the endings need to be the most impactful, and will also have to come with an epilogue for each character.