SEO campaigns take months to improve rankings and it takes a continuous effort of implementing SEO practices and updates for your campaign to be successful.  If you pause your SEO campaign for any reason, your keyword rankings will decline, and your website will start to lose visibility over time.  This will allow your competitors who don’t pause their SEO efforts to take over the high rankings for your keywords.  It will also take additional resources to restore your rankings and visibility after pausing your campaign.