Changes in Parent Luma theme is not reflected in Child Luma theme in Magento 2.3.0?

Question

I have created seven child themes and one parent theme for these seven child themes. All seven child themes points to their parent theme, we've named "Master".

<theme>
    <title>Child Theme 1</title>
    <parent>Company/Child1</parent>
</theme>
<theme>
    <title>Child Theme 2</title>
    <parent>Company/Child2</parent>
</theme>
<theme>
    <title>Child Theme 3</title>
    <parent>Company/Child3</parent>
</theme>

...and so on...

The "Master" parent theme points to "Magento/Luma".

<theme>
    <title>Master</title>
    <parent>Magento/luma</parent>
</theme>

Theme locations:

app/design/frontend/Company/Master
app/design/frontend/Company/Child1
app/design/frontend/Company/Child2
app/design/frontend/Company/Child3

Now to the problem

In the Parent theme "Master" layout file: app/design/frontend/Company/Master/Magento_Catalog/layout/theme.xml

I have added:

<referenceBlock name="catalog.compare.link" remove="true" />
<referenceBlock name="catalog.compare.sidebar" remove="true"/>
<referenceBlock name="catalogsearch.product.addto.compare" remove="true"/>
<referenceBlock name="category.product.addto.compare" remove="true"/>
<referenceBlock name="crosssell.product.addto.compare" remove="true" />
<referenceBlock name="related.product.addto.compare" remove="true" />
<referenceBlock name="upsell.product.addto.compare" remove="true" />
<referenceBlock name="view.addto.compare" remove="true" />

But nothing happens in the seven child themes? Changes does not reflect.

Some questions:

1. app/design/frontend/Magento is empty, no luma theme, nor blank for the parent theme "Master" - is this correct?
2. The parent theme "Master" is pointing to "Magento/Luma" - should it be "Magento/Blank" instead?

Greatly appreciated if someone can help me shed some light on this, Thanks,

Answer 1

I think you have to make some change in the child theme "theme.xml".

You are code is

<theme>
    <title>Child Theme 1</title>
    <parent>Company/Child1</parent>
</theme>
<theme>
    <title>Child Theme 2</title>
    <parent>Company/Child2</parent>
</theme>
<theme>
    <title>Child Theme 3</title>
    <parent>Company/Child3</parent>
</theme>

You need to changed into

<theme>
    <title>Child Theme 1</title>
    <parent>Company/Master</parent>
</theme>
<theme>
    <title>Child Theme 2</title>
    <parent>Company/Master</parent>
</theme>
<theme>
    <title>Child Theme 3</title>
    <parent>Company/Master</parent>
</theme>

Hope this will help you. Thanks