It can. If you rented out your timeshare, or if you sold your timeshare for a profit, that amount could be considered taxable income.
The following article goes into greater detail about when to report rental income and expenses:
https://www.irs.gov/publications/p527/ch01.html#en_US_2016_publink1000218959
https://www.irs.gov/publications/p527/index.html
An exception applies: "There's a special rule if you use a dwelling unit as a residence and rent it for fewer than 15 days. In this case, don't report any of the rental income and don't deduct any expenses as rental expenses."
If you sold your timeshare, you may have received a 1099-S. More details below:
https://ttlc.intuit.com/replies/5165545