[css-writing-modes] proposed 'writing-mode:sideways-*' values: effect on computed value of 'display'

The current Writing Modes draft says:

# If a box has a different block flow direction than its containing block:
#
#    If the box has a specified display of inline, its display computes 
to inline-block. [CSS21]
#    If the box has a specified display of run-in, its display computes 
to block. [CSS21]
#    If the box is a block container, then it establishes a new block 
formatting context.

How (if at all) will this change if the proposal to introduce 
writing-mode:sideways-lr and sideways-rl values is adopted?

I'm assuming we'll go for something along the lines of:

# If a box has a different computed value for writing-mode than its 
containing block, .....

so that in an example like:

   <div style="writing-mode:vertical-lr">Hello World
     <span style="writing-mode:sideways-lr">foo bar</span>
   </div>

the <span>'s display will compute to 'inline-block' rather than 
'inline'. Is this correct?

Thanks,

JK