Should TH be an block tag?

[StokeMasterJack]

TD extends HtmBlockTag while TH extends HtmlInlineTag. Is that correct?

[cy6erGn0m]

<td> and <tr> are neither phrasing nor flow content tags so should not inherit none of these interfaces

[imanushin]

Because of this issue, it is unable to put div into th. It is valid, however div extension requires FlowContent and TH class does not implement it.

[SUPERCILEX]

<td> and <tr> are neither phrasing nor flow content tags so should not inherit none of these interfaces

I believe that's partially incorrect. I've been looking at the spec which says it allows Flow content, but with no header, footer, sectioning content, or heading content descendants. For ease of use, it probably makes sense to have th extend flow content even though some tags would be invalid.