It looks like explicitly stating 'Visible','on' in the call to title() may make the title show up. I'm not sure why this is, since the title 'Visible' property was already 'on' the way you had it. (Of course, the title is still obscured by some of the text objects.)
n = 10;
C = randn(n);
myLabel1 = 'label';
y = triu(repmat(n+1, n, n) - (1:n)') + 0.5;
x = triu(repmat(1:n, n, 1)) + 0.5;
x(x == 0.5) = NaN;
scatter(x(:), y(:), 400.*abs(C(:)), C(:), 'filled', 'MarkerFaceAlpha', 0.6)
% enclose markers in a grid
xl = [1:n+1;repmat(n+1, 1, n+1)];
xl = [xl(:, 1), xl(:, 1:end-1)];
yl = repmat(n+1:-1:1, 2, 1);
line(xl, yl, 'color', 'k') % horizontal lines
line(yl, xl, 'color', 'k') % vertical lines
% show labels
text(1:n, (n:-1:1) + 0.5, myLabel1, 'HorizontalAlignment', 'right')
text((1:n) + 0.5, repmat(n + 1, n, 1), myLabel1, 'HorizontalAlignment', 'right', 'Rotation', 270)
h = gca;
colorbar(h);
h.Visible = 'off';
h.Position(4) = h.Position(4)*0.9;
axis(h, 'equal')
colormap('jet')
% caxis([-1,1]);
title('Your Title', 'FontSize', 10, 'Visible', 'on'); % set title
