In a nutshell, nothing.
When the legislature was debating the 2015 reforms, law enforcement came out with dire warnings. The New Mexico Department of Public safety claimed that ending civil forfeiture would have "a negative impact on public safety" and could trigger a "reduction in criminal investigations." In the bill analysis, the department testified, "This bill directly jeopardizes the most basic and fundamental key to successful narcotics investigations."
The chair of the New Mexico Sheriff's Association simply asserted, "You'll get less law enforcement," without civil asset forfeiture.
It didn't turn out that way.
The Institute for Justice compared crime rates in neighboring Texas and Colorado for its Policing for Profit report and determined that "New Mexico's overall crime rate did not rise following the implementation of strong forfeiture reform in 2015, nor did arrest rates drop."