Reading through the terms for the BMO offer, looks like hey are strict on churning but maybe the system is flawed... Worth a try at least, should still get first year free, maybe just no 30k points

1 BMO Rewards points that are awarded as a welcome bonus are only available to first time new BMO World Elite MasterCard cardholders and will not be awarded to current or former BMO World Elite MasterCard/BMO Rewards World Elite MasterCard cardholders who reinstate a closed account or subsequently open a new account. If a cardholder cancels their BMO World Elite MasterCard within 30 days of opening the account and the annual fee is refunded to the cardholder, the welcome bonus will also be cancelled. The BMO Rewards points which are awarded as a welcome bonus will be reflected on the first statement following the cardholder’s first purchase on the BMO World Elite MasterCard.