Ltd co with one director moving out of the UK

MarieNoelle

My client is a ltd co with two directors equal shareholders (ordinary shares). One of the director has decided to move back to her country of origin for 3-5 years (then return to the UK) but wants to remain a director and shareholder.
They have agreed that only one director will remain on the payroll and to change the shareholding (probably alphabet shares with one category only paying dividends).

Do they need to tell companies house if they do not change the shareholding overall (just different categories of shares)?

Are there any other issues I should be aware of?

I would be grateful for your comments.