A quick Google search for telco churn dataset license landed me at this IBM GitHub page:
Note: This license is specifically for the AI code patterns in the repository (the code) rather than the data, which I believe is again, because data is typically not afforded copyright protection.
Since this is the official IBM GitHub and they share the data with no mention of a license, it is reasonable to assume the data is license free (even if you believed data could have protections). Worst case scenario would be it is covered by the same license as the code which is the super permissive Apache license.
I personally wouldn't even bother trying to track down a lawyer, but, you should do whatever due diligence you feel necessary.