Both the mass spam [#2690] and the Spam Ninja tool [#2442] mark Spam Tracker tickets as "Deleted", however, currently "Deleted" is just a status, and the spam is still visible (the only way currently to remove tracker ticket spam from view is using this form.
As per our Tracker docs: The "Deleted" Tracker item "Status" value does not actually delete Tracker items or remove them from view; this status option is provided for sorting purposes.
At this point, I think it'd (probably) be simpler to simply hide deleted tracker items than to do a removal of those tickets the way the aforementioned form does.
Migrations don't migrate deleted tickets, and migrations are going to be done sooner than this will.