From the site Ludwig.guru. Many examples of "in the next years" in the press and magazines, in technical/scientific and non-technical texts..
"People are mentally stressed by anxiousness about what is coming in the next years".
1
The New York Times
"In the next years, we should have a constitutional democracy plus a market economy".
2
The New York Times
"And in the next years, millions more will move to these places".
3
The New York Times - Magazine
I'm sure that in the next years they will have the last step.
4
The Guardian - Sport
On medical forms in the next years, I confessed my abortion when asked.
5
The New York Times - Magazine
In the next years, Ms. Buechner largely disappeared from public view, though not by choice.
6
The New York Times -
If things were set right, the German economy would grow more in the next years than in the previous ones.
7
The New York Times
"I'm very happy and extremely committed to give everything I have, also in the next years when I'm with them.
8
The Guardian - Sport
The fruits will be borne in the next years.
9
The Journal of Headache and Pain -
So the disposal of these cars is of increasing importance in the next years.
10
Robotics and Autonomous Systems -
In the next years the luminosity of the LHC will be significantly increased.
11
Mechanical Systems and Signal Processing -
The sea will be a source of economic development in the next years.
12
Marine Genomics -
The existing, planned and discussed ECAs are uncertain about their implementation in the next years.
13
Journal of Shipping and Trade -
Possible new SAR missions in the next years include SAOCOM-CS and Tandem-L.
14
Carbon Balance and Management -
In the next years the potential mechanisms of CGRP-mAbs should be explored by pharmacological methods.
15
The Journal of Headache and Pain
In the next years the potential mechanisms of CGRP-mAbs should be explored by pharmacological methods.
Also, please note the scientific contexts in which it appears.
I don't think one can quibble with any of the uses of the phrase in the forgoing examples.
"in the next years" is basically semantically the same as "in the coming years".
Cambridge University:
There are technologies entering the market that will help us bridge
that gap in the next years for blended textiles.
The Institute for Sustainability Leadership
CISL
Oxford University
COVID-19 Government Response Tracker So, in the next years, our
researchers will analyse our authoritative dataset with innovative
quantitative and qualitative methods to delve deeper into different
government responses to the COVID-19 pandemic and shed light on the
causal links between pandemic responses and relevant social,
political, and economic factors.
Covid tracker
Just two examples of university usage in the UK.
Harvard College
At the same time, in the next years, we’re going to do something.
People have been saying that it’s going to be done for a long time,
but it actually is going to be done.
Harvard College Fund
STANFORD MEDICINE MAGAZINE
And how do we respond to other pandemics likely to arise in the next years or decades?
Stanford
[I don't think this is at all strange sounding; in the next years, in the next months, in the next days, in the next eons, in the next decades, etc. are all idiomatic in English. It also is not exactly the same as: in the next few years, etc.]
Another example:
The next years would be difficult for the boy. [subject, noun]
The boy would have difficulties in the next years. [adverbial]