Aithera

Harvard casualty over here as well. Honestly, I'm just really relieved that they've finally made it official!

Whomp, there it is from Harvard.

I thought Harvard wanted to have an idea of who is going to accept their offers to help them firm up the depth of the waitlist and ultimately the rejections, but now I'm not so sure. I unfortunately predict it is as simple as they haven't  hit "send" on the rejection email button on their application software

The job talks were "open" to you as a member of the university community. Information about them was circulated via email, but I doubt very much that it was ever posted on a public-facing website.
Bear in mind that many who make it to the short list for a tenure-track position would be leaving another job, and across industries, it's generally unwise to advertise to one's existing employer that you're eager to move elsewhere, especially when actually receiving the offer is by no means guaranteed...

Any thoughts on Harvard's art history rejection posts but (at least for me, though I think for others too) radio silence on general history apps? 

According to the results page, usually early March/late, late February

Just heard from UMich! Second acceptance! 

Ask about things the website can't really tell you. What is student life like? Are there any history grad student associations? How often do their students present at conferences or publish? Are there opportunities to do those things, and is there any funding for them? How are GA's assigned? Do GA's usually hold office hours? Is there any grad student lounge/lab/study space? What are the demographics of the campus? (side note: this question usually allows you to glen some information about campus politics if you're interested and know how to listen for it). Are there opportunities for interdisciplinary work with other departments? etc...
Mostly ask about things you're interested in. At this stage, W&M has said that they think you are a good fit for them, now you get to decide if *they* are a good fit for *you*.

I am going to assume that you would be getting an MA to bolster your PhD prospects for a future application cycle, as I did. Given that you say you've already received funding information (the most important aspect of choosing a school for an MA, in my opinion), I won't address that. 
You should ask questions that pertain to your thesis research and language abilities. A terminal MA student (with PhD aspirations), I believe, should strive to do at least three things: 1. Bolster your non-English language ability by either strengthening your primary non-English language or beginning work on a second non-English language 2. Gain experience giving conference presentations, preferably not at a graduate student conference, although anything is better than nothing and 3. Produce an MA thesis capable of either being mined for a publishable article or two or else leading to a PhD dissertation. 
With these priorities in mind, you can probably come up with some relevant questions. For example, what language resources are available to the students, and is there room (and funding!) in the MA timeline for you to take an extra language class or two (even if its over the summer)? Is travel funding available to MA students, both for research and conferences? In general, I think an MA student will have a tough time obtaining any sort of international funding, but a bit of cash for a regional archive shouldn't be out of the question. 
Also, most programs offer a non-thesis track history MA. Resist the temptation to go down this route; it will not serve you well when reapplying to PhD programs.