Repeal every one and replace with Canadian Immigration Month. Leave it to communities, cities or provinces to determine what and when to celebrate based on their history, cultural makeup and demographics. Federally, celebrate Canada Day and be done with it.
Here are the heritage months designated federally by the Parliament of Canada (via legislation or House/Senate motions):
•January – Tamil Heritage Month (House motion, 2016)
•February – Black History Month (House motion 1995; Senate 2008)
•March – Irish Heritage Month (House motion, 2021)
•April – Sikh Heritage Month — the federal Parliament voted in November 2018 to celebrate Sikh Heritage Month nationally every April  (Sikh Heritage Month Act, 2019)
•May – Asian Heritage Month (Senate motion, 2001–02)
•May – Canadian Jewish Heritage Month — Parliament passed legislation on March 29, 2018 designating May as Canadian Jewish Heritage Month 
•June – Italian Heritage Month (House motion, 2017)
•June – Filipino Heritage Month — declared by Motion M-155 on October 30, 2018 
•June – Portuguese Heritage Month — the House of Commons designated June as Portuguese Heritage Month on November 8, 2017 
•June – National Indigenous History Month (House motion, 2009)
•October – Islamic History Month (House motion, 2007)
•October – Latin American Heritage Month — designated by the Parliament of Canada in 2018  via the Latin American Heritage Month Act
•October – German Heritage Month (House motion, 2017)
•November – Lebanese Heritage Month (House motion, 2018)
•November – Hindu Heritage Month (House motion, 2022)