Will there be any problems if you leave compileSdkVersion 28 in gradle, but change targetSdkVersion to 29?

Question

Google Play

I wanted to publish a New Year's update for my application, but it turned out that the targetSdkVersion should be 29. O'k. First, I did everything on the recommendation of android studio, i.e. changed compileSdkVersion to 29 too and put buildToolsVersion 29.0.0. And then the refactor->migrate to androidx, but at the same time I caught a bunch of errors, which I sort of coped with. The studio does not swear, and when I compile a signed aab, Google Play writes that the signature is invalid. Then I compiled apk by checking the necessary checkboxes (googled it). Everything seems to be in order, but the application is successfully installed and does not start (apparently there are some errors in the xml, which the studio is silent about). Then I tried to leave everything as in previous versions, changing only the targetSdkVersion to 29. Everything looks okay: Google Play accepts, does not swear at the signature, and the application starts.
Here is the code from gradle:

apply plugin: 'com.android.application'

android {
  useLibrary 'org.apache.http.legacy'
  compileSdkVersion 28
  
  defaultConfig {
    applicationId "com.my.project"
    minSdkVersion 19
    //noinspection OldTargetApi
    targetSdkVersion 29
    versionCode 13
    versionName "12.3"
  }
  buildTypes {
    release {
      minifyEnabled false
      proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
  }
  buildToolsVersion = '28.0.3'
}

dependencies {
  implementation fileTree(dir: 'libs', include: ['*.jar'])
  //noinspection GradleCompatible
  implementation 'com.android.support:appcompat-v7:28.0.0'
  implementation 'com.android.support:design:28.0.0'
implementation 'com.android.support:support-v4:28.0.0'
  //noinspection GradleDependency
  implementation 'com.android.support:appcompat-v7:28.0.0-alpha3'
  //noinspection GradleDependency
  implementation 'com.android.support.constraint:constraint-layout:1.1.2'
  //noinspection GradleDependency
  implementation 'com.android.support:design:28.0.0-alpha3'
    implementation 'org.jetbrains:annotations-java5:15.0'
    implementation 'org.jetbrains:annotations-java5:15.0'
  implementation 'com.android.support:exifinterface:28.0.0'
}
apply plugin: 'com.google.gms.google-services'

In this case, the studio swears at compileSdkVersion 28 (highlights in red and recommends setting 29), but everything compiles, issuing both aab and apk marked "errors 0"
The application is extremely simple - the first page is offline html, and then 99% works on WebView

PS do not judge strictly. Experience, skills and knowledge at the amateur level (did not set out to become a programmer)