Hi Kathryn,
Other than independent sites listing all known or rumored refurbishments in one place, I haven't found a specific link on the disneyworld.com site offering a compiled list of refurbishments. I do, however, rely on the notifications specifically listed on the attraction page. For instance, the
Jungle Cruise link currently offers a message regarding the temporary closing.
Some of the most popular independent sites like allears.net or wdwinfo.com will offer a helpful list, updated frequently. Just keep in mind refurbishment schedules are always subject to change. You can check the Tip Board at the central hub of the Theme Parks to learn of unexpected closures upon your arrival. The good news is, Walt Disney World offers so many forms of entertainment and attractions, I assure you temporary refurbishments will not dampen your experience!
Wishing you a magical vacation, Kathryn, and please visit us again with any other planning questions coming to mind.
Sherri