This would be amazing if possible. ^
Thirded. Accent information is something I could have used a lot earlier in my Japanese education. Not sure why more resources don't talk about it.
I'll investigate the possibility of adding pitch accent information.
One reason it might not be talked about much in is that the accent varies from region to region and that in most cases it's not needed to resolve ambiguity.
While it may not be strictly needed, saying words with the proper accent is important for sounding natural and saying things in a way that a native speaker can parse easily. English dictionaries mark which syllable has the emphasis; a Japanese dictionary should too, in my opinion.
If it helps, I found a pitch accent database here: https://github.com/javdejong/nhk-pronunciation but the licensing is not very clear. From https://ankiweb.net/shared/info/932119536 "I was not certain about the direct usage of the database of NHK Nihongo Hatsuon Akusento Jiten (NHK日本語発音アクセント辞典). I have therefore chosen to only use a derivative version"
The NHK database is most likely under copyright and I'd be surprised if they allowed others to publish it. The first site you linked looks very good, but I can most likely not incorporate their data into Jisho. Linking to it from each entry should be no problem though.
Pitch accent
I'm wondering if it would be possible to partner with http://www.gavo.t.u-tokyo.ac.jp/ojad/ (or any other provider of pitch accent data) to show pitch accent for common words? It's the only thing I can think of that could make Jisho even more awesome.