Reverting Referenced Subsystems back to normal Subsystems

refSubsystem = 'subsys20b';
modelName = 'modelRefSubsys20b';
open_system(modelName);

oldBlock = [ modelName '/Subsystem Reference'];
newBlock = [ modelName '/subsystem'];

% create a copy of the referenced subsystem
add_block('built-in/Subsystem', newBlock)
Simulink.BlockDiagram.copyContentsToSubsystem(refSubsystem, newBlock)

% Retrieve useful info from the old block
t1 = get_param(oldBlock, 'Portconnectivity');
t2 = get_param(oldBlock, 'PortHandles');
t3 = get_param(newBlock, 'PortHandles');

% delete old lines
h = get_param(oldBlock, 'LineHandles');
ni = numel(h.Inport);
no = numel(h.Outport);
delete_line(h.Inport);
delete_line(h.Outport);

% create connections to new block
for i=1:numel(t2.Inport)
    srcBkhdl = t1(i).SrcBlock; % source block handle
    srcNm = getfullname(srcBkhdl); % source block name
    srcBkPts = get_param(srcNm, 'PortHandles'); % source block port handles
    srcPt = srcBkPts.Outport(t1(i).SrcPort+1); % source port
    dstPt = t3.Inport(i); % destination port
    add_line(modelName, srcPt, dstPt);
end

% create connections from new block
for i=1:numel(t2.Outport)
    dstBkhdl = t1(ni+i).DstBlock; % dest block handle
    dstNm = getfullname(dstBkhdl); % dest block name
    dstBkPts = get_param(dstNm, 'PortHandles'); % dest block port handles
    dstPt = dstBkPts.Inport(t1(ni+i).DstPort+1); % dest port
    srcPt = t3.Outport(i); % src port
    add_line(modelName, srcPt, dstPt);
end

% copy to same position
pos = get_param(oldBlock, 'position');
set_param(newBlock, 'position', pos);

% remove old block
delete_block(oldBlock);

% save changes
save_system(modelName);

% replace_block might work.. Haven't tried
% replace_block(modelName, 'Subsystem Reference', 'subsystem')