Couple questions for the OP (and others confirming this bug):
1) Did you see the Great Mill in queue with lots of turns remaining before the reload?
I have seen the announcements not always take place when something wonderful gets built but then get announced when starting up the game. I'm not saying a bug didn't take place but the more details we have the less likely we are to waste developer time chasing the wrong ghosts.
2) For everyone seeing entire queues instantly cleared on restarts ARE YOU SEEING ALL THOSE BUILDINGS NOW LISTED on the structure list for that city?
I've never seen a city suddenly built up in a turn (been around since they announced they were atoning for Elemental). Bugs happen but more details would help a ton. The AI's often change their queue lists. I've seen production queues change radically at times when the AI rethinks it's strategy but not seen those disappeared queued buildings get built. Also some info doesn't appear to be loaded up when restarting a game until a turn goes by...example, the diplomatic plus and minus list. Reloading a game could easily be a trigger for the AI to "rethink" what it is doing and wipe it's list.
I'm not saying these things aren't bugged. Bugs of this magnitude would be game breakers. Just that we need to nail it down with the full details or false bugs will lead to real bugs not getting fixed.
I've been in beta since near the start and not seen much in the way of confirmed game breakers. Two crash to desktops ever, not witmessed sudden seismic shifts in power. Concerns that reloading might be confusing the AI into losing turns with sudden shifts in it's thinking (even the best AI's need a lot of help against real players and can't afford such schitzophrenic shifts). Lots of little bugs but three accusations and misunderstandings for every real one.
Some real bugs:
--XP operating systems seem to have a confirmed major memory leak (true bug). The leak isn't universal though. Windows 7 (at least with my main stream slightly dated rig appears to have not have the problem, at least not to anywhere near the same degree). Windows 8 has it's own issues.
--Opponent scores suddenly jumping has been a common complaint and could be a hint towards a game breaking problem requiring major changes in the coding. More likely reality.... I have seen scores change abruptly when the AI "rethinks" it's strategy and sends it's stationed units out from the towns housing them. Watch how fast their scores change when they go to war. Suddenly faction scores change wildly! Why? Because it appears that faction score is your military power ranking and the real bug may be that units in towns don't get added to the score. (These numbers only get checked between turns). There may be more to it than that...heroes may always count or player troops may be scored accurately but not AI's or certain AI's, etc. The point being that accusations without all the details can lead to looking in the wrong directions.
Couple lesser bugs...
--Pioneer quest that doesn't give a pioneer if you fight instead of pay for the unit...confirmed bug...has it been confirmed that no pioneer is given if there is room for the pioneer to join your group? In other words, is the bug that there is never a pioneer when you fight or that a pioneer doesn't get added unless there is a space in your group?
--Shadowbolt doesn't get Warlock or other damage % adds although the tooltip shows as if these bonuses will be added. This is a tooltip bug. Shadowbolt is working as intended (based on a reply many months ago). There is no elemental resistance to shadowbolt so they took away it's bonuses to keep it from being over powered.
--Probably the biggest set of bugs in the game is how horribly out of date the tooltip info is. The game has changed a ton in many little ways with pretty much all the tweaking being for the better. The obsolete tooltips cause a great amount of frustration (even to those that know the real info at times) and frankly leads to a lot of misinformation being handed back to the dev's. Cleaning these up might be a big job but is an attainable way to help us all.
(Edited for typos).