The phrase "unfettered expansion" means a growth or increase without any restrictions or limitations. It refers to the idea of free and unrestricted expansion or development. Full definition
The report held the assumption that unfettered expansion of the Alberta tar sands would happen regardless of politics, economics, or the climate. (toronto350.org)
The result is almost unfettered expansion. (neatoday.org)
The 2000s saw an unfettered expansion from a simple trio of... (carbase.my)