You can still do it, from within outlook web access and publish your calendar. It will make an ICS file on the exchange server but you would need to copy the file weekly or something and put it locally on the pi.
Something like this, not sure what version of Exchange your running but its basically the same from 2010, and 2013. It will give you the link to the ICS file. Again, this is all for not if your exchange admins don’t allow calendar publishing, but it should work inside your office regardless.
https://kb.intermedia.net/article/2530