Files set at beforeProgramValidate stage are no longer picked up during validation of other real .bs files

[iBicha]

Context: https://rokudevelopers.slack.com/archives/CKF1QQGTY/p1739742183565309
Creating an issue in case we lose access to Slack post after a while

I believe this was introduced here #993

repro project
https://github.com/iBicha/bsc-sample-repro

I was able to simplfy the sample even further to be very minimalist. It comes down to this: from 0.68.5 to 0.69.0, .bs files set at beforeProgramValidate stage are no longer picked up during validation of other real .bs files. Here's the full example:
main.bs

import "pkg:/source/AsyncTask/Tasks.bs"

sub main()
    print Tasks.MyTask
end sub

plugin

export class AsyncTaskPlugin implements CompilerPlugin {
    public name = 'AsyncTaskPlugin';

    beforeProgramValidate(program: Program) {
        const fileContent = `enum Tasks
    MyTask = "_AsyncTask"
end enum
`
        program.setFile('source/AsyncTask/Tasks.bs', fileContent);
    }
}

Works with 0.68.5 but with 0.69.0 Tasks is not defined in the source scope
Does this ring any bells?

I can see running bslint that some things are now running out of order (or perhaps is a race condition)
E.g.
with 0.68.5 Validating project finished was printed after afterProgramValidate, with 0.69.0 Validating project finished is printed before afterProgramValidate 0.69.0.txt 0.68.5.txt