Such situations should be addressed both from technical and management perspective, few of the things that needs to addressed are :
1. Does the team consist of only single QA ?
If the team consist of just single QA who would be responsible for the entire automation, then choosing a programming language that is alien to current team will create a dependency.
If any unforeseen situation comes up then the effort require to maintain the framework would be pretty huge. The organisation need to find a replacement and cannot use in-house resource to fill this position.
2. Does development team writes automation scripts ?
If the process involves dev team pitching in to help automation team then it is recommended to use the same language among dev and test.
But if it is not the case, then you should evaluate whether it really worth putting effort in learning a new language and slowing down the process.
3. What is the expected time period ?
Does the project need to be released quickly , then the focus should be on having an effective regression test framework than programming language.
4. Is there any plan to scale the automation team?
If there is a plan to extent the automation team then you could avoid the situation in "Question 1" . You could avoid creating dependency by hiring more java test automation experts and up skill any in-house resources. So you could start working on an effective java framework that would be easy to be maintained by future test engineers.
5. What is the future plans of the team?
Is there any plans to move into angular based stuffs infuture, are the project going to come up something new? . Ask more of such questions and choose the tools and languages accordingly.