Yes, it is an erosion that would be sought to be built on in the next contract.
Erosion of the ratio is the right description, over time the ratio has been flipped, from allowing 5 imports on the field at one time, to today were it's almost the opposite. Interesting that as early as 1952 they explored the "Naturalized Canadian" rule, a.k.a., the "Canadianized American".
Here is a brief history.
The rules on imports were wide open in the CFL?s formative years, until the Winnipeg Pegs became the first western team to win the Grey Cup in 1935 with eight imports on the roster, led by the legendary Fritzie Hanson.
Residency requirements were established the following year, which led to the 1936 western champ Regina Roughriders declining their trip to the Grey Cup rather than play without five key imports.
Finally in 1946, the Canadian Rugby Union ? the precursor to the CFL ? allowed five imports. In 1950, the limit was raised to seven. In 1952 it was changed again to allow seven imports as well as allowing Americans with four years of experience to be counted as non-imports.
In 1954 ? generally recognized as the start of the modern era of Canadian football ? the quota was raised to 10 non-imports. In 1955 the four year rule was scrapped but western teams carried 12 Americans. By 1959 both the Eastern Big Four and the Western Interprovincial Rugby Football Union were up to 12 Americans on a roster of 27.
A landmark decision was made in 1961 with the ?Naturalized Canadian? rule, a.k.a., the ?Canadianized American?. The rule granted non-import status to players who had acquired Canadian citizenship after five years of residency in the country. Essentially this meant that rosters were set at 34, with 15 imports.
Of course, teams started to take advantage of this rule, so in 1965 number of Naturalized Canadians on each roster was limited to three. However, one player who was released due to this new quota went marching off to the Ontario Human Rights Commission, which ruled that it was unlawful to discriminate employment based on citizenship, threatening all roster management.
Cue Bora Laskin, who was the Dean of Law at Osgoode Hall in Toronto, and later the Chief Justice of the Supreme Court of Canada. Laskin found a way out for the newly formed Canadian Football League. The solution was to base any distinction not on a player?s nationality, citizenship or residence but on his early football training.
If the training was received inside Canada, he was a ?non-import?. Outside of Canada, he was an ?import?. The definition has withstood challenges from the Canadian and Ontario Human Rights Commissions since 1965.
From there, through the 1970?s, the number of imports slowly crept upward. From 14 to 15 in 1972, to removing quarterbacks from the ratio mix in 1986 with the import number falling to 13, then edging its way upward to the present day of a roster ratios. Today teams are made up of 42 players, including three quarterbacks and 39 other players, of which 19 may be imports. Essentially this leaves teams with 22 imports total and only seven Canadian starters.
https://www.cfl.ca/2011/02/11/mullin-changing-the-game-the-ratio/