Through purchasing aggregator submissions with BrightLocal, your listings are managed and marked with a trusted data stamp for 12 months. This also enables you to update your listing for free within this 12 month period.
Local search experts recommend keeping your aggregator listings claimed and trusted.
The major benefit of renewing your submission to data aggregators is that your data retains it's 'trusted' status within aggregator feeds to 3rd party sites. This means that 3rd party sites see this data as being more 'official' and are less likely to overwrite it with data that has been crawled/imported from other sources.
Your data won't get deleted from the third-party sites because they buy it from the aggregators and the data is useful to them, but you will no longer be able to update the data on your listing.
There is a renewal fee to repurchase your submissions to the aggregators and keep your data's 'trusted' status. The renewal fee is the same as for the initial submission/update.