If so, where's the evidence that this is the case?
Some experts disagree with that method of stopping the beetle plague, and think that the forest should heal itself. Other experts don't want just to watch dying forest and try to do something. Hence the argument.
Because experts are divided, this is a great opportunity to attack the government. Unfortunately there is no substantive discussion, even here on HN.
Try to guess if current Polish government is left or right wing.
[1] https://en.wikipedia.org/wiki/European_spruce_bark_beetle
In this case I've heard that major opinion for the government was prepared by an forestry expert whose lifelong expertise is in chainsaw mechanics with no standing in biology community, whereas Nature regularly publishes alarmed letters from experts in actual ecology of outbreaks.
Prima facie, this does not reduce their credibility.
"In western North America, the current outbreak of the mountain pine beetle and its microbial associates has destroyed wide areas of lodgepole pine forest, including more than 16 million of the 55 million hectares of forest in British Columbia. The current outbreak in the Rocky Mountain National Park began in 1996 and has caused the destruction of millions of acres of ponderosa and lodgepole pine trees. According to an annual assessment by the state's forest service, 264,000 acres of trees in Colorado were infested by the mountain pine beetle at the beginning of 2013. This was much smaller than the 1.15 million acres that were affected in 2008 because the beetle has already killed off most of the vulnerable trees"
Of course something similar cannot happen in Poland.
[1] https://en.m.wikipedia.org/wiki/Mountain_pine_beetle