The title is set like this:
<span class="rz-cell-data" title="@(column.Template == null ? column.GetValue(Item) : "")">
So yes, when Template is set the title attribute remains empty. You can add your own HTML element wrapper with a title attribute set per your requirements e.g.
<Template>
<span title="@context.TitleProperty">
@context.FirstName @context.LastName
</span>
</Template>