The Single Class Surface Combatant continues to be the guiding principle for the destroyer and eventually the frigate replacement programs. This may change with the new Shipbuilding policy being developed but until then I'll stick with this line of thought.
Other vessel types will be first to have new steel cut, such as the replenishment ships, but the fighting ships will start with the destroyers. There is always concern with cost but I have not read anywhere that the numbers would be reduced, rather the number of ships would remain the same but the crewing needs will be reduced through automation. The hull costs should remain manageable but the likely largest expenditures will be on capabilities. Radars and weapons for the destroyers will be substantial as Canada prepares to negate the threat of ballistic and surface to surface missiles being developed by countries such as Iran, N Korea, etc. The follow-on frigates will be the same hull but outfitted to a much lesser degree, with limited anti-air. The commonality will enable the ability to add "destroyer capabilities" if needed as the spaces for more VLS and the radar suites already exist.
Attachment:
IROQUOIS NEW BUILD 8.GIF